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Knight Capital Group LLC – ‘10-Q’ for 6/30/11 – ‘EX-101.LAB’

On:  Tuesday, 8/9/11, at 4:02pm ET   ·   For:  6/30/11   ·   Accession #:  1193125-11-216460   ·   File #:  1-14223

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  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 8/09/11  Knight Capital Group LLC          10-Q        6/30/11   89:8.1M                                   Donnelley … Solutions/FA

Quarterly Report   —   Form 10-Q   —   Sect. 13 / 15(d) – SEA’34
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Quarterly Report                                    HTML    792K 
 2: EX-31.1     Certification of Chief Executive Officer Pursuant   HTML     33K 
                to Section 302                                                   
 3: EX-31.2     Certification of Chief Financial Officer Pursuant   HTML     33K 
                to Section 302                                                   
 4: EX-32.1     Certification of Chief Executive Officer Pursuant   HTML     28K 
                to Section 906                                                   
 5: EX-32.2     Certification of Chief Financial Officer Pursuant   HTML     28K 
                to Section 906                                                   
18: R1          Document and Entity Information                     HTML     46K 
78: R2          Consolidated Statements of Operations               HTML    133K 
13: R3          Consolidated Statements of Financial Condition      HTML    139K 
14: R4          Consolidated Statements of Financial Condition      HTML     42K 
                (Parenthetical)                                                  
64: R5          Consolidated Statements of Cash Flows               HTML    180K 
37: R6          Organization and Description of the Business        HTML     40K 
71: R7          Significant Accounting Policies                     HTML     83K 
28: R8          Fair Value of Financial Instruments                 HTML    168K 
38: R9          Collateralized Transactions                         HTML     35K 
45: R10         Receivable from and Payable to Brokers, Dealers     HTML     40K 
                and Clearing Organizations                                       
57: R11         Investments                                         HTML     39K 
22: R12         Goodwill and Intangible Assets                      HTML    100K 
35: R13         Long-Term Debt                                      HTML     65K 
30: R14         Comprehensive Income                                HTML     45K 
33: R15         Stock-Based Compensation                            HTML     78K 
72: R16         Income Taxes                                        HTML     46K 
27: R17         Writedown Of Assets And Lease Loss Accrual          HTML     30K 
53: R18         Discontinued Operations                             HTML     58K 
31: R19         Earnings Per Share                                  HTML     58K 
77: R20         Significant Clients                                 HTML     30K 
58: R21         Commitments and Contingent Liabilities              HTML     72K 
65: R22         Financial Instruments with Off-Balance Sheet Risk   HTML     34K 
                and Concentrations of Credit Risk                                
17: R23         Business Segments                                   HTML     64K 
68: R24         Subsequent Event                                    HTML     33K 
26: R25         Significant Accounting Policies (Policy)            HTML    137K 
20: R26         Significant Accounting Policies (Tables)            HTML     46K 
23: R27         Fair Value of Financial Instruments (Tables)        HTML    156K 
47: R28         Receivable from and Payable to Brokers, Dealers     HTML     39K 
                and Clearing Organizations (Tables)                              
63: R29         Investments (Tables)                                HTML     38K 
52: R30         Goodwill and Intangible Assets (Tables)             HTML     98K 
40: R31         Long-Term Debt (Tables)                             HTML     44K 
34: R32         Comprehensive Income (Tables)                       HTML     40K 
50: R33         Stock-Based Compensation (Tables)                   HTML     72K 
76: R34         Income Taxes (Tables)                               HTML     40K 
29: R35         Discontinued Operations (Tables)                    HTML     55K 
79: R36         Earnings Per Share (Tables)                         HTML     55K 
89: R37         Commitments and Contingent Liabilities (Tables)     HTML     60K 
25: R38         Organization and Description of the Business        HTML     30K 
                (Details)                                                        
61: R39         Significant Accounting Policies (Narrative)         HTML     29K 
                (Details)                                                        
39: R40         Significant Accounting Policies (Schedule of        HTML     30K 
                Interest Income and Interest Expense) (Details)                  
51: R41         Significant Accounting Policies (Component of Net   HTML     34K 
                Trading Revenue Includes Dividend Income and                     
                Expense) (Details)                                               
46: R42         Fair Value of Financial Instruments (Narrative)     HTML     32K 
                (Details)                                                        
24: R43         Fair Value of Financial Instruments (Financial      HTML    106K 
                Assets and Liabilities Measured at Fair Value on a               
                Recurring Basis) (Details)                                       
66: R44         Fair Value of Financial Instruments (Fair Value of  HTML     46K 
                Derivative Instruments Effect of Changes in Fair                 
                Value on Statements of Operations) (Details)                     
86: R45         Fair Value of Financial Instruments (Fair Value of  HTML     52K 
                Derivative Instruments Gain (Loss) Recognized)                   
                (Details)                                                        
87: R46         Collateralized Transactions (Details)               HTML     45K 
21: R47         Receivable from and Payable to Brokers, Dealers     HTML     46K 
                and Clearing Organizations (Schedule of Amounts                  
                Receivable from and Payable to Brokers, Dealers                  
                and Clearing Organizations) (Details)                            
19: R48         Investments (Summary of Investments) (Details)      HTML     42K 
83: R49         Goodwill and Intangible Assets (Narrative)          HTML     45K 
                (Details)                                                        
12: R50         Goodwill and Intangible Assets (Goodwill and        HTML     38K 
                Intangible Assets, Net of Accumulated                            
                Amortization) (Details)                                          
43: R51         Goodwill and Intangible Assets (Intangible Assets,  HTML     53K 
                Net of Accumulated Amortization) (Details)                       
36: R52         Goodwill and Intangible Assets (Amortization        HTML     31K 
                Expense) (Details)                                               
16: R53         Goodwill and Intangible Assets (Estimated           HTML     45K 
                Amortization Expense) (Details)                                  
88: R54         Long-Term Debt (Narrative) (Details)                HTML    148K 
73: R55         Long-Term Debt (Summary Of Long-Term Debt)          HTML     38K 
                (Details)                                                        
54: R56         Long-Term Debt (Schedule of Recorded Expenses with  HTML     36K 
                Respect to Notes) (Details)                                      
84: R57         Comprehensive Income (Schedule of Comprehensive     HTML     45K 
                Income) (Details)                                                
41: R58         Stock-Based Compensation (Narrative) (Details)      HTML     45K 
74: R59         Stock-Based Compensation (Employee Compensation     HTML     32K 
                and Benefits, Restricted Awards) (Details)                       
42: R60         Stock-Based Compensation (Summary of Restricted     HTML     58K 
                Awards Activity) (Details)                                       
56: R61         Stock-Based Compensation (Compensation Expense      HTML     33K 
                Relating to Stock Options) (Details)                             
49: R62         Stock-Based Compensation ( Summary of Stock Option  HTML     60K 
                Activity) (Details)                                              
60: R63         Income Taxes (Schedule Of Reconciliation Of         HTML     43K 
                Federal Statutory Income Tax Rate to the Company's               
                Actual Income Tax Rate From Continuing Operations                
                (Details)                                                        
44: R64         Writedown Of Assets And Lease Loss Accrual          HTML     30K 
                (Details)                                                        
59: R65         Discontinued Operations (Schedule of Losses from    HTML     47K 
                Discontinued Operations Net of Tax) (Details)                    
48: R66         Discontinued Operations (Schedule of Discontinued   HTML     44K 
                Operations Assets and Liabilities Recorded in                    
                Other Assets and Accrued Expenses and Other                      
                Liabilities) (Details)                                           
85: R67         Earnings Per Share (Narrative) (Details)            HTML     33K 
70: R68         Earnings Per Share (Schedule of Calculation of      HTML     62K 
                Numerator and Denominator in Earnings Per Share)                 
                (Details)                                                        
75: R69         Significant Clients (Details)                       HTML     31K 
62: R70         Commitments and Contingent Liabilities (Narrative)  HTML     39K 
                (Details)                                                        
15: R71         Commitments and Contingent Liabilities (Schedule    HTML     58K 
                of Lease and Contract Obligations) (Details)                     
69: R72         Commitments and Contingent Liabilities (Fair Value  HTML     30K 
                of Assets or Liability on Future Contract)                       
                (Details)                                                        
32: R73         Commitments and Contingent Liabilities (Schedule    HTML     30K 
                of Realized Gain (Loss) on Future Contracts)                     
                (Details)                                                        
55: R74         Business Segments (Income (Loss) from Continuing    HTML     49K 
                Operations before Income Taxes (Pre-tax Earnings)                
                and Total Assets by Segment) (Details)                           
81: R75         Subsequent Event (Details)                          HTML     35K 
80: XML         IDEA XML File -- Filing Summary                      XML    154K 
82: EXCEL       IDEA Workbook of Financial Reports (.xls)            XLS   1.32M 
 6: EX-101.INS  XBRL Instance -- kcg-20110630                        XML   2.19M 
 8: EX-101.CAL  XBRL Calculations -- kcg-20110630_cal                XML    194K 
 9: EX-101.DEF  XBRL Definitions -- kcg-20110630_def                 XML    400K 
10: EX-101.LAB  XBRL Labels -- kcg-20110630_lab                      XML   1.05M 
11: EX-101.PRE  XBRL Presentations -- kcg-20110630_pre               XML    830K 
 7: EX-101.SCH  XBRL Schema -- kcg-20110630                          XSD    185K 
67: ZIP         XBRL Zipped Folder -- 0001193125-11-216460-xbrl      Zip    165K

‘EX-101.LAB’   —   XBRL Labels — kcg-20110630_lab

This Exhibit is an XBRL XML File.

                                                                                                                                                                                
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<roleRef xlink:type="simple" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-roles-2011-01-31.xsd#newConcept" roleURI="http://fasb.org/us-gaap/role/label/newConcept"/>
<roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodStartLabel" roleURI="http://www.xbrl.org/2009/role/negatedPeriodStartLabel"/>
<labelLink xlink:type="extended" xlink:role="http://www.xbrl.org/2003/role/link">
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DocumentAndEntityInformationAbstract_lbl" xml:lang="en-US"> Document And Entity Information [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DocumentAndEntityInformationAbstract_lbl" xml:lang="en-US"> Document and Entity Information </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementTable_lbl" xml:lang="en-US"> Statement [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_StatementClassOfStockAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xml:lang="en-US"> Class of Stock [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ClassOfStockDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfStockDomain_lbl" xml:lang="en-US"> Class of Stock [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonClassAMember" xlink:to="us-gaap_CommonClassAMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonClassAMember_lbl" xml:lang="en-US"> Class A Common Stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonClassBMember" xlink:to="us-gaap_CommonClassBMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonClassBMember_lbl" xml:lang="en-US"> Class B Common Stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementLineItems_lbl" xml:lang="en-US"> Statement [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_DocumentType" xlink:label="dei_DocumentType"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentType_lbl" xml:lang="en-US"> Document Type </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US"> Amendment Flag </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodEndDate" xlink:to="dei_DocumentPeriodEndDate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentPeriodEndDate_lbl" xml:lang="en-US"> Document Period End Date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalYearFocus" xlink:to="dei_DocumentFiscalYearFocus_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalYearFocus_lbl" xml:lang="en-US"> Document Fiscal Year Focus </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalPeriodFocus" xlink:to="dei_DocumentFiscalPeriodFocus_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xml:lang="en-US"> Document Fiscal Period Focus </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_TradingSymbol_lbl" xml:lang="en-US"> Trading Symbol </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityRegistrantName_lbl" xml:lang="en-US"> Entity Registrant Name </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCentralIndexKey_lbl" xml:lang="en-US"> Entity Central Index Key </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US"> Current Fiscal Year End Date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFilerCategory" xlink:to="dei_EntityFilerCategory_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityFilerCategory_lbl" xml:lang="en-US"> Entity Filer Category </label>
<loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2011/dei-2011-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xml:lang="en-US"> Entity Common Stock, Shares Outstanding </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xml:lang="en-US"> Consolidated Statements of Operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="us-gaap_RevenuesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenuesAbstract" xlink:to="us-gaap_RevenuesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenuesAbstract_lbl" xml:lang="en-US"> Revenues </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FeesAndCommissions" xlink:label="us-gaap_FeesAndCommissions"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FeesAndCommissions" xlink:to="us-gaap_FeesAndCommissions_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FeesAndCommissions_lbl" xml:lang="en-US"> Commissions and fees </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FeesAndCommissions_lbl" xml:lang="en-US"> Fees and Commissions, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FeesAndCommissions_lbl" xml:lang="en-US"> Fees </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TradingGainsLosses" xlink:label="us-gaap_TradingGainsLosses"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradingGainsLosses" xlink:to="us-gaap_TradingGainsLosses_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TradingGainsLosses_lbl" xml:lang="en-US"> Net trading revenue </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="us-gaap_InterestIncomeExpenseNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestIncomeExpenseNet" xlink:to="us-gaap_InterestIncomeExpenseNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestIncomeExpenseNet_lbl" xml:lang="en-US"> Interest Income (Expense), Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestIncomeExpenseNet_lbl" xml:lang="en-US"> Interest, net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InterestIncomeExpenseNet_lbl" xml:lang="en-US"> Interest Income (Expense), Net, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InvestmentIncomeNonoperating" xlink:label="us-gaap_InvestmentIncomeNonoperating"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentIncomeNonoperating" xlink:to="us-gaap_InvestmentIncomeNonoperating_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentIncomeNonoperating_lbl" xml:lang="en-US"> Investment Income And Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_InvestmentIncomeNonoperating_lbl" xml:lang="en-US"> Income (loss) related to foreign currency adjustments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InvestmentIncomeNonoperating_lbl" xml:lang="en-US"> Investment income (loss) and other, net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InvestmentIncomeNonoperating_lbl" xml:lang="en-US"> Investment Income, Nonoperating, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InvestmentIncomeNonoperating_lbl" xml:lang="en-US"> Investment income loss and other, net </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Revenues" xlink:label="us-gaap_Revenues"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Revenues" xlink:to="us-gaap_Revenues_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Revenues_lbl" xml:lang="en-US"> Total revenues </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Revenues_lbl" xml:lang="en-US"> Total revenues </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_Revenues_lbl" xml:lang="en-US"> Revenues </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpensesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpensesAbstract_lbl" xml:lang="en-US"> Expenses </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LaborAndRelatedExpense" xlink:label="us-gaap_LaborAndRelatedExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LaborAndRelatedExpense" xlink:to="us-gaap_LaborAndRelatedExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LaborAndRelatedExpense_lbl" xml:lang="en-US"> Employee compensation and benefits </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LaborAndRelatedExpense_lbl" xml:lang="en-US"> Labor and Related Expense, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FloorBrokerageExchangeAndClearanceFees" xlink:label="us-gaap_FloorBrokerageExchangeAndClearanceFees"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FloorBrokerageExchangeAndClearanceFees" xlink:to="us-gaap_FloorBrokerageExchangeAndClearanceFees_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FloorBrokerageExchangeAndClearanceFees_lbl" xml:lang="en-US"> Execution and clearance fees </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FloorBrokerageExchangeAndClearanceFees_lbl" xml:lang="en-US"> Floor Brokerage, Exchange and Clearance Fees, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OrderFlowFees" xlink:label="us-gaap_OrderFlowFees"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrderFlowFees" xlink:to="us-gaap_OrderFlowFees_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OrderFlowFees_lbl" xml:lang="en-US"> Payments for order flow </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommunicationsAndInformationTechnology" xlink:label="us-gaap_CommunicationsAndInformationTechnology"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommunicationsAndInformationTechnology" xlink:to="us-gaap_CommunicationsAndInformationTechnology_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommunicationsAndInformationTechnology_lbl" xml:lang="en-US"> Communications and data processing </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CommunicationsAndInformationTechnology_lbl" xml:lang="en-US"> Communications and Information Technology, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="us-gaap_DepreciationAndAmortization"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationAndAmortization" xlink:to="us-gaap_DepreciationAndAmortization_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xml:lang="en-US"> Depreciation and amortization </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xml:lang="en-US"> Depreciation, Depletion and Amortization, Nonproduction, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestExpense" xlink:label="us-gaap_InterestExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US"> Interest </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US"> Interest Expense, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US"> Interest Expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessDevelopment" xlink:label="us-gaap_BusinessDevelopment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessDevelopment" xlink:to="us-gaap_BusinessDevelopment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessDevelopment_lbl" xml:lang="en-US"> Business development </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LeaseAndRentalExpense" xlink:label="us-gaap_LeaseAndRentalExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseAndRentalExpense" xlink:to="us-gaap_LeaseAndRentalExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseAndRentalExpense_lbl" xml:lang="en-US"> Operating Leases, Rent Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LeaseAndRentalExpense_lbl" xml:lang="en-US"> Occupancy and equipment rentals </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LeaseAndRentalExpense_lbl" xml:lang="en-US"> Operating Leases, Rent Expense, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LeaseAndRentalExpense_lbl" xml:lang="en-US"> Rental expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProfessionalFees" xlink:label="us-gaap_ProfessionalFees"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfessionalFees" xlink:to="us-gaap_ProfessionalFees_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProfessionalFees_lbl" xml:lang="en-US"> Professional fees </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_WriteDownOfAssetsAndLeaseLossAccrualBenefitNet" xlink:label="kcg_WriteDownOfAssetsAndLeaseLossAccrualBenefitNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_WriteDownOfAssetsAndLeaseLossAccrualBenefitNet" xlink:to="kcg_WriteDownOfAssetsAndLeaseLossAccrualBenefitNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_WriteDownOfAssetsAndLeaseLossAccrualBenefitNet_lbl" xml:lang="en-US"> The Company's policy is to identify excess real estate capacity and where applicable, accrue for related future costs, net of estimated sub-lease income. In the event the Company is able to sublease the excess real estate after recording a lease loss, such accrual is adjusted to the extent the actual terms of sub-leased property differ from the assumptions used in the calculation of the accrual. In the event that the Company concludes that previously determined excess real estate is needed for the Company's use, such lease loss accrual is adjusted accordingly. Also includes writedown of assets. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_WriteDownOfAssetsAndLeaseLossAccrualBenefitNet_lbl" xml:lang="en-US"> Write Down Of Assets And Lease Loss Accrual Benefit Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_WriteDownOfAssetsAndLeaseLossAccrualBenefitNet_lbl" xml:lang="en-US"> Writedown of assets and lease loss accrual </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="kcg_WriteDownOfAssetsAndLeaseLossAccrualBenefitNet_lbl" xml:lang="en-US"> Lease loss accrual </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherExpenses" xlink:label="us-gaap_OtherExpenses"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherExpenses" xlink:to="us-gaap_OtherExpenses_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherExpenses_lbl" xml:lang="en-US"> Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OtherExpenses_lbl" xml:lang="en-US"> Other Expenses, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpenses_lbl" xml:lang="en-US"> Total expenses </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingExpenses_lbl" xml:lang="en-US"> Total expenses </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xml:lang="en-US"> Income Loss From Continuing Operations Before Income Taxes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xml:lang="en-US"> Income from continuing operations before income taxes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xml:lang="en-US"> Pre-tax earnings </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Income tax expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Income Tax Expense (Benefit), Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperations" xlink:label="us-gaap_IncomeLossFromContinuingOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperations" xlink:to="us-gaap_IncomeLossFromContinuingOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperations_lbl" xml:lang="en-US"> Income from continuing operations, net of tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperations_lbl" xml:lang="en-US"> Income from continuing operations, net of tax </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl" xml:lang="en-US"> Income (loss) from discontinued operations, net of tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl" xml:lang="en-US"> Loss from discontinued operations, net of tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl" xml:lang="en-US"> Loss from discontinued operations, net of tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl" xml:lang="en-US"> Loss from discontinued operations, net of tax </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> Net income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> Net income used in basic calculations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> Net income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> Net Income </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsPerBasicShare" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerBasicShare"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerBasicShare_lbl" xml:lang="en-US"> Basic earnings per share from continuing operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerBasicShare_lbl" xml:lang="en-US"> Income (Loss) from Continuing Operations, Per Outstanding Share, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare" xlink:to="us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare_lbl" xml:lang="en-US"> Diluted earnings per share from continuing operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasic" xlink:to="us-gaap_EarningsPerShareBasic_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xml:lang="en-US"> Basic earnings per share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xml:lang="en-US"> Basic earnings per share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xml:lang="en-US"> Basic earnings per share </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareDiluted" xlink:to="us-gaap_EarningsPerShareDiluted_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xml:lang="en-US"> Diluted earnings per share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xml:lang="en-US"> Diluted earnings per share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xml:lang="en-US"> Diluted earnings per share </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xml:lang="en-US"> Shares used in computation of basic earnings per share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xml:lang="en-US"> Income and shares used in basic calculations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xml:lang="en-US"> Income and shares used in basic calculations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xml:lang="en-US"> Shares used in computation of diluted earnings per share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xml:lang="en-US"> Income and shares used in diluted calculations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xml:lang="en-US"> Income and shares used in diluted calculations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xml:lang="en-US"> Consolidated Statements of Financial Condition </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsAbstract_lbl" xml:lang="en-US"> ASSETS </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetsAbstract_lbl" xml:lang="en-US"> ASSETS </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US"> Cash and cash equivalents </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US"> Cash and cash equivalents at end of period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US"> Cash and cash equivalents at beginning of period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US"> Cash and Cash Equivalents, at Carrying Value, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FinancialInstrumentsOwnedAtFairValue" xlink:label="us-gaap_FinancialInstrumentsOwnedAtFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancialInstrumentsOwnedAtFairValue" xlink:to="us-gaap_FinancialInstrumentsOwnedAtFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinancialInstrumentsOwnedAtFairValue_lbl" xml:lang="en-US"> Financial instruments owned, at fair value, including securities pledged of $812,379 in 2010 and $212,425 in 2009 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FinancialInstrumentsOwnedAtFairValue_lbl" xml:lang="en-US"> Financial instruments owned, at fair value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FinancialInstrumentsOwnedAtFairValue_lbl" xml:lang="en-US"> Financial Instruments, Owned, at Fair Value, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinancialInstrumentsOwnedAtFairValue_lbl" xml:lang="en-US"> Financial instruments owned, at fair value, including instruments pledged of $1,141,223 at June 30, 2011 and $812,379 at December 31, 2010 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CollateralizedAgreementsAbstract" xlink:label="us-gaap_CollateralizedAgreementsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CollateralizedAgreementsAbstract" xlink:to="us-gaap_CollateralizedAgreementsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CollateralizedAgreementsAbstract_lbl" xml:lang="en-US"> Collateralized agreements: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SecuritiesBorrowed" xlink:label="us-gaap_SecuritiesBorrowed"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SecuritiesBorrowed" xlink:to="us-gaap_SecuritiesBorrowed_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SecuritiesBorrowed_lbl" xml:lang="en-US"> Securities borrowed </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations" xlink:label="us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations" xlink:to="us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_lbl" xml:lang="en-US"> Receivable from brokers, dealers and clearing organizations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_lbl" xml:lang="en-US"> Receivable from brokers, dealers and clearing organizations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Property Plant And Equipment Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Property, Plant and Equipment, Net, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Property, Plant and Equipment, Net, Beginning Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Fixed assets and leasehold improvements, at cost, less accumulated depreciation and amortization of $118,552 in 2010 and $128,045 in 2009 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Property, Plant and Equipment, Net, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Fixed assets and leasehold improvements, at cost, less accumulated depreciation and amortization </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Investments" xlink:label="us-gaap_Investments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Investments" xlink:to="us-gaap_Investments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Investments_lbl" xml:lang="en-US"> Investments, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Investments_lbl" xml:lang="en-US"> Investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Investments_lbl" xml:lang="en-US"> Total Investments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Goodwill" xlink:to="us-gaap_Goodwill_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US"> Goodwill </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US"> Goodwill, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US"> Goodwill, Beginning Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US"> Goodwill, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xml:lang="en-US"> Intangible assets, less accumulated amortization of $51,141 in 2010 and $38,018 in 2009 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xml:lang="en-US"> Intangible Assets, Net (Excluding Goodwill), Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xml:lang="en-US"> Intangible assets, less accumulated amortization </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherAssets" xlink:label="us-gaap_OtherAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssets" xlink:to="us-gaap_OtherAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssets_lbl" xml:lang="en-US"> Other assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OtherAssets_lbl" xml:lang="en-US"> Other Assets, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US"> Total assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US"> Total assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US"> LIABILITIES & EQUITY </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US"> LIABILITIES & EQUITY </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue" xlink:label="us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue" xlink:to="us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_lbl" xml:lang="en-US"> Financial instruments sold, not yet purchased, at fair value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_lbl" xml:lang="en-US"> Financial instruments sold, not yet purchased, at fair value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_lbl" xml:lang="en-US"> Financial Instruments Sold, Not yet Purchased, at Fair Value, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_lbl" xml:lang="en-US"> Fair value of purchased call options </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CollateralizedFinancingsAbstract" xlink:label="us-gaap_CollateralizedFinancingsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CollateralizedFinancingsAbstract" xlink:to="us-gaap_CollateralizedFinancingsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CollateralizedFinancingsAbstract_lbl" xml:lang="en-US"> Collateralized financings: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SecuritiesLoaned" xlink:label="us-gaap_SecuritiesLoaned"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SecuritiesLoaned" xlink:to="us-gaap_SecuritiesLoaned_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SecuritiesLoaned_lbl" xml:lang="en-US"> Securities loaned </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase" xlink:to="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_lbl" xml:lang="en-US"> Securities Sold under Agreements to Repurchase </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_lbl" xml:lang="en-US"> Financial instruments sold under agreements to repurchase </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_PayableToGnmaTrust" xlink:label="kcg_PayableToGnmaTrust"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_PayableToGnmaTrust" xlink:to="kcg_PayableToGnmaTrust_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_PayableToGnmaTrust_lbl" xml:lang="en-US"> Payable To Gnma Trust </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_PayableToGnmaTrust_lbl" xml:lang="en-US"> Payable To Gnma Trust </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_PayableToGnmaTrust_lbl" xml:lang="en-US"> Liability to GNMA trusts </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherSecuredFinancings" xlink:label="us-gaap_OtherSecuredFinancings"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherSecuredFinancings" xlink:to="us-gaap_OtherSecuredFinancings_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherSecuredFinancings_lbl" xml:lang="en-US"> Other secured financings </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PayablesToBrokerDealersAndClearingOrganizations" xlink:label="us-gaap_PayablesToBrokerDealersAndClearingOrganizations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PayablesToBrokerDealersAndClearingOrganizations" xlink:to="us-gaap_PayablesToBrokerDealersAndClearingOrganizations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PayablesToBrokerDealersAndClearingOrganizations_lbl" xml:lang="en-US"> Payable to brokers, dealers and clearing organizations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PayablesToBrokerDealersAndClearingOrganizations_lbl" xml:lang="en-US"> Payable to brokers, dealers and clearing organizations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US"> Employee-related Liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US"> Employee-related Liabilities, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US"> Accrued compensation expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccruedLiabilitiesCurrentAndNoncurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US"> Accrued Liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US"> Accrued Liabilities, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US"> Accrued expenses and other liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebt" xlink:label="us-gaap_LongTermDebt"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebt" xlink:to="us-gaap_LongTermDebt_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US"> Long-term Debt, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US"> Long-term debt </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US"> Long-term Debt, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US"> Net balance of long-term debt </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US"> Total liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US"> Total liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_lbl" xml:lang="en-US"> Equity </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Class A common stock Shares authorized: 500,000 at December 31, 2010 and at December 31, 2009; Shares issued: 162,818 at December 31, 2010 and 158,641 at December 31, 2009; Shares outstanding: 97,736 at December 31, 2010 and 92,791 at December 31, 2009 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Common Stock, Value, Issued, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Common Stock, Value, Issued, Beginning Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Common Stock, Value, Issued, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Shares authorized: 500,000 at June 30, 2011 and at December 31, 2010; Shares issued: 166,398 at June 30, 2011 and 162,818 at December 31, 2010; Shares outstanding: 100,343 at June 30, 2011and 97,736 at December 31, 2010 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xml:lang="en-US"> Additional paid-in capital </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xml:lang="en-US"> Additional Paid in Capital, Common Stock, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xml:lang="en-US"> Additional Paid in Capital, Common Stock, Beginning Balance </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US"> Retained earnings </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US"> Retained Earnings (Accumulated Deficit), Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US"> Retained Earnings (Accumulated Deficit), Beginning Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US"> Retained Earnings (Accumulated Deficit), Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="us-gaap_TreasuryStockValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockValue" xlink:to="us-gaap_TreasuryStockValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US"> Treasury stock, at cost; 64,576 shares at September 30, 2010 and 65,850 shares at December 31, 2009 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US"> Treasury stock, at cost; 66,055 at June 30, 2011and 65,082 shares at December 31, 2010 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US"> Treasury Stock, Value, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US"> Treasury Stock, Value, Beginning Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US"> Treasury stock, at cost; 65,965 at March 31, 2011 and 65,082 shares at December 31, 2010 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US"> Accumulated other comprehensive loss </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US"> Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US"> Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US"> Accumulated Other Comprehensive Income (Loss), Net of Tax, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Total Knight Capital Group, Inc. stockholders' equity </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Stockholders' Equity Attributable to Parent, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Stockholders' Equity Attributable to Parent, Beginning Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Total Knight Capital Group, Inc. stockholders' equity </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MinorityInterest" xlink:label="us-gaap_MinorityInterest"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterest" xlink:to="us-gaap_MinorityInterest_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinorityInterest_lbl" xml:lang="en-US"> Noncontrolling interests </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_MinorityInterest_lbl" xml:lang="en-US"> Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_MinorityInterest_lbl" xml:lang="en-US"> Stockholders' Equity Attributable to Noncontrolling Interest, Beginning Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_MinorityInterest_lbl" xml:lang="en-US"> Stockholders' Equity Attributable to Noncontrolling Interest, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US"> Total equity </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US"> Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US"> Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US"> Total equity </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US"> Total liabilities and equity </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US"> Total liabilities and equity </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US"> Notional Value </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue" xlink:label="us-gaap_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue" xlink:to="us-gaap_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue_lbl" xml:lang="en-US"> Financial instruments owned, at fair value, securities pledged </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue_lbl" xml:lang="en-US"> Pledged Assets Separately Reported, Securities Pledged as Collateral, at Fair Value, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xml:lang="en-US"> Class A common stock, shares authorized </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xml:lang="en-US"> Class A common stock, shares issued </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xml:lang="en-US"> Common Stock, Shares, Issued, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Class A common stock, shares outstanding </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Common Stock, Shares, Outstanding, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Common Stock, Shares, Outstanding, Beginning Balance </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="us-gaap_TreasuryStockShares"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockShares" xlink:to="us-gaap_TreasuryStockShares_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockShares_lbl" xml:lang="en-US"> Treasury stock, shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_TreasuryStockShares_lbl" xml:lang="en-US"> Treasury Stock, Shares, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_TreasuryStockShares_lbl" xml:lang="en-US"> Treasury Stock, Shares, Beginning Balance </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xml:lang="en-US"> Consolidated Statements of Cash Flows </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Cash flows from operating activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Adjustments to reconcile income from continuing operations, net of tax to net cash provided by (used in) operating activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Adjustments to reconcile income from continuing operations, net of tax to net cash provided by (used in) operating activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US"> Share-based Compensation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US"> Share-based Compensation, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US"> Stock-based compensation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:to="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_lbl" xml:lang="en-US"> Debt discount accretion and other debt related expenses </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_lbl" xml:lang="en-US"> Debt discount accretion and other debt related expenses </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherNoncashIncome" xlink:label="us-gaap_OtherNoncashIncome"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNoncashIncome" xlink:to="us-gaap_OtherNoncashIncome_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNoncashIncome_lbl" xml:lang="en-US"> Deferred rent </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_OtherNoncashIncome_lbl" xml:lang="en-US"> Deferred rent </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_UnrealizedGainLossOnInvestments" xlink:label="us-gaap_UnrealizedGainLossOnInvestments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrealizedGainLossOnInvestments" xlink:to="us-gaap_UnrealizedGainLossOnInvestments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrealizedGainLossOnInvestments_lbl" xml:lang="en-US"> Unrealized loss (gain) on investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_UnrealizedGainLossOnInvestments_lbl" xml:lang="en-US"> Unrealized (gain) loss on investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_UnrealizedGainLossOnInvestments_lbl" xml:lang="en-US"> Unrealized Gain (Loss) on Investments, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" xlink:label="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" xlink:to="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_lbl" xml:lang="en-US"> Operating activities from discontinued operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingAssetsAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingAssetsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingAssetsAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingAssetsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingAssetsAbstract_lbl" xml:lang="en-US"> (Increase) in operating assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities" xlink:label="us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities_lbl" xml:lang="en-US"> Increase (Decrease) in Financial Instruments Used in Operating Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities_lbl" xml:lang="en-US"> Financial instruments owned, at fair value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities_lbl" xml:lang="en-US"> Increase (Decrease) in Financial Instruments Used in Operating Activities, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInSecuritiesBorrowed" xlink:label="us-gaap_IncreaseDecreaseInSecuritiesBorrowed"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInSecuritiesBorrowed" xlink:to="us-gaap_IncreaseDecreaseInSecuritiesBorrowed_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInSecuritiesBorrowed_lbl" xml:lang="en-US"> Increase (Decrease) in Securities Borrowed </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInSecuritiesBorrowed_lbl" xml:lang="en-US"> Securities borrowed </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInBrokerageReceivables" xlink:label="us-gaap_IncreaseDecreaseInBrokerageReceivables"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInBrokerageReceivables" xlink:to="us-gaap_IncreaseDecreaseInBrokerageReceivables_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInBrokerageReceivables_lbl" xml:lang="en-US"> Increase (Decrease) in Brokerage Receivables </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInBrokerageReceivables_lbl" xml:lang="en-US"> Receivable from brokers, dealers and clearing organizations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xml:lang="en-US"> Increase (Decrease) in Other Operating Assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xml:lang="en-US"> Other assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xml:lang="en-US"> Increase (Decrease) in Other Operating Assets, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingLiabilitiesAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingLiabilitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingLiabilitiesAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingLiabilitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingLiabilitiesAbstract_lbl" xml:lang="en-US"> Increase (decrease) in operating liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased" xlink:label="us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased" xlink:to="us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased_lbl" xml:lang="en-US"> Increase (Decrease) in Financial Instruments Sold, Not yet Purchased </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased_lbl" xml:lang="en-US"> Financial instruments sold, not yet purchased, at fair value </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions" xlink:label="us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions" xlink:to="us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions_lbl" xml:lang="en-US"> Increase (Decrease) in Securities Loaned Transactions </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions_lbl" xml:lang="en-US"> Securities loaned </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements" xlink:label="us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements" xlink:to="us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements_lbl" xml:lang="en-US"> Increase (Decrease) in Payables under Repurchase Agreements </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements_lbl" xml:lang="en-US"> Financial instruments sold under agreements to repurchase </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_IncreaseDecreaseInOtherSecuredFinancings" xlink:label="kcg_IncreaseDecreaseInOtherSecuredFinancings"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_IncreaseDecreaseInOtherSecuredFinancings" xlink:to="kcg_IncreaseDecreaseInOtherSecuredFinancings_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_IncreaseDecreaseInOtherSecuredFinancings_lbl" xml:lang="en-US"> The net change during the reporting period in the secured financing other than securities sold under agreements to repurchase and securities loaned. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_IncreaseDecreaseInOtherSecuredFinancings_lbl" xml:lang="en-US"> Increase (Decrease) in Other Secured Financings </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="kcg_IncreaseDecreaseInOtherSecuredFinancings_lbl" xml:lang="en-US"> Other secured financings </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_IncreaseDecreasInPayableToGnmaTrust" xlink:label="kcg_IncreaseDecreasInPayableToGnmaTrust"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_IncreaseDecreasInPayableToGnmaTrust" xlink:to="kcg_IncreaseDecreasInPayableToGnmaTrust_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_IncreaseDecreasInPayableToGnmaTrust_lbl" xml:lang="en-US"> Increase Decreas In Payable To Gnma Trust </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_IncreaseDecreasInPayableToGnmaTrust_lbl" xml:lang="en-US"> Increase Decreas In Payable To Gnma Trust </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="kcg_IncreaseDecreasInPayableToGnmaTrust_lbl" xml:lang="en-US"> Liability to GNMA trusts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_IncreaseDecreasInPayableToGnmaTrust_lbl" xml:lang="en-US"> Liability to GNMA trusts </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInPayablesToBrokerDealers" xlink:label="us-gaap_IncreaseDecreaseInPayablesToBrokerDealers"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPayablesToBrokerDealers" xlink:to="us-gaap_IncreaseDecreaseInPayablesToBrokerDealers_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInPayablesToBrokerDealers_lbl" xml:lang="en-US"> Increase Decrease In Payables To Broker Dealers </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInPayablesToBrokerDealers_lbl" xml:lang="en-US"> Payable to brokers, dealers and clearing organizations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_lbl" xml:lang="en-US"> Increase (Decrease) in Employee Related Liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_lbl" xml:lang="en-US"> Increase (Decrease) in Employee Related Liabilities, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_lbl" xml:lang="en-US"> Accrued compensation expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_lbl" xml:lang="en-US"> Increase (Decrease) in Accrued expenses and other liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_lbl" xml:lang="en-US"> Accrued expenses and other liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US"> Net cash used in operating activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US"> Net cash provided by (used in) operating activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xml:lang="en-US"> Cash flows from investing activities </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ProceedsFromDistributionsReceivedFromInvestments" xlink:label="kcg_ProceedsFromDistributionsReceivedFromInvestments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ProceedsFromDistributionsReceivedFromInvestments" xlink:to="kcg_ProceedsFromDistributionsReceivedFromInvestments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ProceedsFromDistributionsReceivedFromInvestments_lbl" xml:lang="en-US"> The Company has several equity investments in which it received distributions. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ProceedsFromDistributionsReceivedFromInvestments_lbl" xml:lang="en-US"> Proceeds From Distributions Received From Investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ProceedsFromDistributionsReceivedFromInvestments_lbl" xml:lang="en-US"> Distributions from investments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquireInvestments" xlink:label="us-gaap_PaymentsToAcquireInvestments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireInvestments" xlink:to="us-gaap_PaymentsToAcquireInvestments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireInvestments_lbl" xml:lang="en-US"> Purchases of investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireInvestments_lbl" xml:lang="en-US"> Purchases of investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PaymentsToAcquireInvestments_lbl" xml:lang="en-US"> Payments to Acquire Investments, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US"> Purchases of fixed assets and leasehold improvements </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US"> Purchases of fixed assets and leasehold improvements </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US"> Payments to Acquire Property, Plant, and Equipment, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries" xlink:label="us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries" xlink:to="us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries_lbl" xml:lang="en-US"> Purchase of noncontrolling interest </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries_lbl" xml:lang="en-US"> Purchase of noncontrolling interest </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" xlink:to="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_lbl" xml:lang="en-US"> Cash Provided by (Used in) Investing Activities, Discontinued Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_lbl" xml:lang="en-US"> Investing activities from discontinued operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US"> Net cash (used in) provided by investing activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US"> Net cash (used in) provided by investing activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xml:lang="en-US"> Cash flows from financing activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="us-gaap_ProceedsFromLinesOfCredit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromLinesOfCredit" xlink:to="us-gaap_ProceedsFromLinesOfCredit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xml:lang="en-US"> Proceeds from Lines of Credit </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xml:lang="en-US"> Proceeds from term credit agreement </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xml:lang="en-US"> Proceeds from Lines of Credit, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xml:lang="en-US"> Proceeds from credit facility </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromConvertibleDebt" xlink:label="us-gaap_ProceedsFromConvertibleDebt"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromConvertibleDebt" xlink:to="us-gaap_ProceedsFromConvertibleDebt_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromConvertibleDebt_lbl" xml:lang="en-US"> Proceeds from issuance of cash convertible notes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="us-gaap_RepaymentsOfLinesOfCredit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfLinesOfCredit" xlink:to="us-gaap_RepaymentsOfLinesOfCredit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfLinesOfCredit_lbl" xml:lang="en-US"> Repayment of credit facility </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RepaymentsOfLinesOfCredit_lbl" xml:lang="en-US"> Repayment of credit facility </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_PurchaseOfCallOptions" xlink:label="kcg_PurchaseOfCallOptions"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_PurchaseOfCallOptions" xlink:to="kcg_PurchaseOfCallOptions_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_PurchaseOfCallOptions_lbl" xml:lang="en-US"> The cash outflow associated with the purchase of a call options related to cash convertible note offering. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_PurchaseOfCallOptions_lbl" xml:lang="en-US"> Purchase of Call Options </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="kcg_PurchaseOfCallOptions_lbl" xml:lang="en-US"> Purchase of call options </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromIssuanceOfWarrants" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfWarrants" xlink:to="us-gaap_ProceedsFromIssuanceOfWarrants_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants_lbl" xml:lang="en-US"> Proceeds from issuance of warrants </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants_lbl" xml:lang="en-US"> Warrants sold to purchase shares </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromStockOptionsExercised" xlink:to="us-gaap_ProceedsFromStockOptionsExercised_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xml:lang="en-US"> Proceeds From Stock Options Exercised </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xml:lang="en-US"> Stock options exercised </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:to="us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_lbl" xml:lang="en-US"> Income tax benefit related to stock-based compensation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_lbl" xml:lang="en-US"> Income tax benefit related to stock-based compensation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:to="us-gaap_PaymentsForRepurchaseOfCommonStock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock_lbl" xml:lang="en-US"> Cost of common stock repurchased </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock_lbl" xml:lang="en-US"> Cost of common stock repurchased </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Financing Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US"> Net cash provided by financing activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:label="us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:to="us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_lbl" xml:lang="en-US"> Effect of exchange rate changes on cash and cash equivalents </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_lbl" xml:lang="en-US"> Effect of Exchange Rate on Cash and Cash Equivalents, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl" xml:lang="en-US"> Increase (decrease) in cash and cash equivalents </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl" xml:lang="en-US"> Increase (decrease) in cash and cash equivalents </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xml:lang="en-US"> Supplemental disclosure of cash flow information: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestPaid" xlink:label="us-gaap_InterestPaid"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaid" xlink:to="us-gaap_InterestPaid_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPaid_lbl" xml:lang="en-US"> Cash paid for interest </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InterestPaid_lbl" xml:lang="en-US"> Interest Paid, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxesPaid" xlink:label="us-gaap_IncomeTaxesPaid"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxesPaid" xlink:to="us-gaap_IncomeTaxesPaid_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxesPaid_lbl" xml:lang="en-US"> Cash paid for income taxes </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_OrganizationAndDescriptionOfBusinessAbstract" xlink:label="kcg_OrganizationAndDescriptionOfBusinessAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_OrganizationAndDescriptionOfBusinessAbstract" xlink:to="kcg_OrganizationAndDescriptionOfBusinessAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_OrganizationAndDescriptionOfBusinessAbstract_lbl" xml:lang="en-US"> Organization And Description Of The Business [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_OrganizationAndDescriptionOfBusinessAbstract_lbl" xml:lang="en-US"> Organization and Description of the Business </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NatureOfOperations" xlink:label="us-gaap_NatureOfOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NatureOfOperations" xlink:to="us-gaap_NatureOfOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NatureOfOperations_lbl" xml:lang="en-US"> Nature Of Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NatureOfOperations_lbl" xml:lang="en-US"> Organization and Description of the Business </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_AccountingPoliciesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xml:lang="en-US"> Significant Accounting Policies </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US"> Significant Accounting Policies Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US"> Significant Accounting Policies </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueDisclosuresAbstract_lbl" xml:lang="en-US"> Fair Value of Financial Instruments </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl" xml:lang="en-US"> Fair Value Disclosures Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl" xml:lang="en-US"> Fair Value of Financial Instruments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl" xml:lang="en-US"> Fair Value of Financial Instruments </label>
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<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfFinancialInstrumentsOwnedAndPledgedAsCollateralTextBlock" xlink:label="us-gaap_ScheduleOfFinancialInstrumentsOwnedAndPledgedAsCollateralTextBlock"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfFinancialInstrumentsOwnedAndPledgedAsCollateralTextBlock_lbl" xml:lang="en-US"> Schedule Of Financial Instruments Owned And Pledged As Collateral Text Bloc </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfFinancialInstrumentsOwnedAndPledgedAsCollateralTextBlock_lbl" xml:lang="en-US"> Collateralized Transactions </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DueToAndFromBrokerDealersAndClearingOrganizationsAbstract_lbl" xml:lang="en-US"> Receivable from and Payable to Brokers, Dealers and Clearing Organizations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DueToAndFromBrokerDealersAndClearingOrganizationsDisclosure" xlink:label="us-gaap_DueToAndFromBrokerDealersAndClearingOrganizationsDisclosure"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DueToAndFromBrokerDealersAndClearingOrganizationsDisclosure_lbl" xml:lang="en-US"> ReceivaDueToAndFromBrokerDealersAndClearingOrganizationsDisclosureble from and Payable to brokers, dealers and clearing organizations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DueToAndFromBrokerDealersAndClearingOrganizationsDisclosure_lbl" xml:lang="en-US"> Receivable from and Payable to Brokers, Dealers and Clearing Organizations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DueToAndFromBrokerDealersAndClearingOrganizationsDisclosure_lbl" xml:lang="en-US"> Receivable from and Payable to Brokers, Dealers and Clearing Organizations </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentsAbstract_lbl" xml:lang="en-US"> Investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InvestmentsAbstract_lbl" xml:lang="en-US"> Investments Abstract </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="invest_InvestmentTextBlock_lbl" xml:lang="en-US"> Investment [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="invest_InvestmentTextBlock_lbl" xml:lang="en-US"> Investments </label>
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<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_lbl" xml:lang="en-US"> Goodwill And Intangible Assets Disclosure Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_lbl" xml:lang="en-US"> Goodwill and Intangible Assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebtAbstract" xlink:label="us-gaap_LongTermDebtAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtAbstract" xlink:to="us-gaap_LongTermDebtAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtAbstract_lbl" xml:lang="en-US"> Long-Term Debt </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtTextBlock_lbl" xml:lang="en-US"> Long Term Debt Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtTextBlock_lbl" xml:lang="en-US"> Long-Term Debt and Credit Facility </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LongTermDebtTextBlock_lbl" xml:lang="en-US"> Long-Term Debt </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:label="us-gaap_ComprehensiveIncomeNetOfTaxAbstract"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComprehensiveIncomeNetOfTaxAbstract_lbl" xml:lang="en-US"> Comprehensive Income </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComprehensiveIncomeNoteTextBlock_lbl" xml:lang="en-US"> Comprehensive Income Note Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ComprehensiveIncomeNoteTextBlock_lbl" xml:lang="en-US"> Comprehensive Income </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationAllocationAndClassificationInFinancialStatementsAbstract" xlink:label="us-gaap_ShareBasedCompensationAllocationAndClassificationInFinancialStatementsAbstract"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationAllocationAndClassificationInFinancialStatementsAbstract_lbl" xml:lang="en-US"> Stock-Based Compensation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xml:lang="en-US"> Disclosure of Compensation Related Costs, Share-based Payments [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xml:lang="en-US"> Stock-Based Compensation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxExpenseBenefitAbstract" xlink:label="us-gaap_IncomeTaxExpenseBenefitAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefitAbstract" xlink:to="us-gaap_IncomeTaxExpenseBenefitAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExpenseBenefitAbstract_lbl" xml:lang="en-US"> Income Taxes </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xml:lang="en-US"> Income Tax Disclosure Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xml:lang="en-US"> Income Taxes </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_WritedownOfAssetsAndLeaseLossAccrualAbstract" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualAbstract"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualAbstract_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualAbstract_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_WritedownOfAssetsAndLeaseLossAccrualTextBlock" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualTextBlock"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualTextBlock_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualTextBlock_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualTextBlock_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxAbstract" xlink:label="us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxAbstract"/>
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<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock" xlink:label="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xml:lang="en-US"> Earnings Per Share </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xml:lang="en-US"> Earnings Per Share Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xml:lang="en-US"> Earnings Per Share </label>
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<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_SignificantClientsAbstract" xlink:to="kcg_SignificantClientsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_SignificantClientsAbstract_lbl" xml:lang="en-US"> Significant Clients [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_SignificantClientsAbstract_lbl" xml:lang="en-US"> Significant Clients </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DisclosureOfSegmentsMajorCustomersExplanatory_lbl" xml:lang="en-US"> Disclosure Of Segments Major Customers Explanatory </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DisclosureOfSegmentsMajorCustomersExplanatory_lbl" xml:lang="en-US"> Disclosure Of Segments Major Customers Explanatory </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_DisclosureOfSegmentsMajorCustomersExplanatory_lbl" xml:lang="en-US"> Significant Clients </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xml:lang="en-US"> Commitments and Contingent Liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US"> Commitments And Contingencies Disclosure Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US"> Commitments and Contingent Liabilities </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskAbstract" xlink:label="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskAbstract" xlink:to="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskAbstract_lbl" xml:lang="en-US"> Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskAbstract_lbl" xml:lang="en-US"> Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskTextBlock" xlink:label="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskTextBlock" xlink:to="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskTextBlock_lbl" xml:lang="en-US"> Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskTextBlock_lbl" xml:lang="en-US"> Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="kcg_FinancialInstrumentsWithOffBalanceSheetRiskAndConcentrationsOfCreditRiskTextBlock_lbl" xml:lang="en-US"> Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SegmentReportingMeasurementDisclosuresAbstract" xlink:label="us-gaap_SegmentReportingMeasurementDisclosuresAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingMeasurementDisclosuresAbstract" xlink:to="us-gaap_SegmentReportingMeasurementDisclosuresAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingMeasurementDisclosuresAbstract_lbl" xml:lang="en-US"> Business Segments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xml:lang="en-US"> Segment Reporting Disclosure Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xml:lang="en-US"> Business Segments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SubsequentEventsAbstract" xlink:label="us-gaap_SubsequentEventsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsAbstract" xlink:to="us-gaap_SubsequentEventsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsAbstract_lbl" xml:lang="en-US"> Subsequent Event </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="us-gaap_SubsequentEventsTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsTextBlock" xlink:to="us-gaap_SubsequentEventsTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xml:lang="en-US"> Subsequent Events [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xml:lang="en-US"> Subsequent Event </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessCombinationsPolicy" xlink:label="us-gaap_BusinessCombinationsPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationsPolicy" xlink:to="us-gaap_BusinessCombinationsPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationsPolicy_lbl" xml:lang="en-US"> Business Combinations Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_BusinessCombinationsPolicy_lbl" xml:lang="en-US"> Basis of Consolidation and form of Presentation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:to="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl" xml:lang="en-US"> Cash and Cash Equivalents, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl" xml:lang="en-US"> Cash and Cash Equivalents </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MarketableSecuritiesTradingSecuritiesPolicy" xlink:label="us-gaap_MarketableSecuritiesTradingSecuritiesPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketableSecuritiesTradingSecuritiesPolicy" xlink:to="us-gaap_MarketableSecuritiesTradingSecuritiesPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MarketableSecuritiesTradingSecuritiesPolicy_lbl" xml:lang="en-US"> Marketable Securities, Trading Securities, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_MarketableSecuritiesTradingSecuritiesPolicy_lbl" xml:lang="en-US"> Market-making, Trading and Sales Activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:to="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl" xml:lang="en-US"> Fair Value of Financial Instruments, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl" xml:lang="en-US"> Fair Value of Financial Instruments </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_SecuritizationActivitiesPolicyTextBlock" xlink:label="kcg_SecuritizationActivitiesPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_SecuritizationActivitiesPolicyTextBlock" xlink:to="kcg_SecuritizationActivitiesPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_SecuritizationActivitiesPolicyTextBlock_lbl" xml:lang="en-US"> Securitization Activities [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_SecuritizationActivitiesPolicyTextBlock_lbl" xml:lang="en-US"> Securitization Activities [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="kcg_SecuritizationActivitiesPolicyTextBlock_lbl" xml:lang="en-US"> Securitization Activities </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_CollateralizedAgreementsAndFinancingsPolicyTextBlock" xlink:label="kcg_CollateralizedAgreementsAndFinancingsPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_CollateralizedAgreementsAndFinancingsPolicyTextBlock" xlink:to="kcg_CollateralizedAgreementsAndFinancingsPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_CollateralizedAgreementsAndFinancingsPolicyTextBlock_lbl" xml:lang="en-US"> Collateralized Agreements and Financings [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_CollateralizedAgreementsAndFinancingsPolicyTextBlock_lbl" xml:lang="en-US"> Collateralized Agreements and Financings [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_CollateralizedAgreementsAndFinancingsPolicyTextBlock_lbl" xml:lang="en-US"> Collateralized Agreements and Financings </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InvestmentPolicyTextBlock" xlink:label="us-gaap_InvestmentPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentPolicyTextBlock" xlink:to="us-gaap_InvestmentPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentPolicyTextBlock_lbl" xml:lang="en-US"> Investment, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InvestmentPolicyTextBlock_lbl" xml:lang="en-US"> Investments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" xlink:label="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" xlink:to="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock_lbl" xml:lang="en-US"> Goodwill and Intangible Assets, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock_lbl" xml:lang="en-US"> Goodwill and Intangible Assets </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_TreasuryStockPolicyTextBlock" xlink:label="kcg_TreasuryStockPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_TreasuryStockPolicyTextBlock" xlink:to="kcg_TreasuryStockPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_TreasuryStockPolicyTextBlock_lbl" xml:lang="en-US"> Treasury Stock [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_TreasuryStockPolicyTextBlock_lbl" xml:lang="en-US"> Treasury Stock [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="kcg_TreasuryStockPolicyTextBlock_lbl" xml:lang="en-US"> Treasury Stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" xlink:to="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl" xml:lang="en-US"> Foreign Currency Transactions and Translations Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl" xml:lang="en-US"> Foreign Currency Translation and Foreign Currency Forward Contracts </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_SoftDollarExpensePolicyTextBlock" xlink:label="kcg_SoftDollarExpensePolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_SoftDollarExpensePolicyTextBlock" xlink:to="kcg_SoftDollarExpensePolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_SoftDollarExpensePolicyTextBlock_lbl" xml:lang="en-US"> Soft Dollar Expense [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_SoftDollarExpensePolicyTextBlock_lbl" xml:lang="en-US"> Soft Dollar Expense [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_SoftDollarExpensePolicyTextBlock_lbl" xml:lang="en-US"> Soft Dollar Expense </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_DepreciationAmortizationAndOccupancyPolicyTextBlock" xlink:label="kcg_DepreciationAmortizationAndOccupancyPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_DepreciationAmortizationAndOccupancyPolicyTextBlock" xlink:to="kcg_DepreciationAmortizationAndOccupancyPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DepreciationAmortizationAndOccupancyPolicyTextBlock_lbl" xml:lang="en-US"> Depreciation Amortization and Occupancy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DepreciationAmortizationAndOccupancyPolicyTextBlock_lbl" xml:lang="en-US"> Depreciation Amortization and Occupancy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_DepreciationAmortizationAndOccupancyPolicyTextBlock_lbl" xml:lang="en-US"> Depreciation, Amortization and Occupancy </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LeaseLossAccrualBenefitNetPolicyTextBlock" xlink:label="kcg_LeaseLossAccrualBenefitNetPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LeaseLossAccrualBenefitNetPolicyTextBlock" xlink:to="kcg_LeaseLossAccrualBenefitNetPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LeaseLossAccrualBenefitNetPolicyTextBlock_lbl" xml:lang="en-US"> Disclosure of accounting policy is to identify excess real estate capacity and where applicable, accrue for related future costs, net of estimated sub-lease income. In the event the Company is able to sublease the excess real estate after recording a lease loss, such accrual is adjusted to the extent the actual terms of sub-leased property differ from the assumptions used in the calculation of the accrual. In the event that the Company concludes that previously determined excess real estate is needed for the Company's use, such lease loss accrual is adjusted accordingly. Also includes writedown of assets, when applicable. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LeaseLossAccrualBenefitNetPolicyTextBlock_lbl" xml:lang="en-US"> Lease Loss Accrual Benefit Net Policy Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_LeaseLossAccrualBenefitNetPolicyTextBlock_lbl" xml:lang="en-US"> Lease Loss Accrual </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xml:lang="en-US"> Income Tax, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xml:lang="en-US"> Income Taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DiscontinuedOperationsPolicyTextBlock" xlink:label="us-gaap_DiscontinuedOperationsPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationsPolicyTextBlock" xlink:to="us-gaap_DiscontinuedOperationsPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DiscontinuedOperationsPolicyTextBlock_lbl" xml:lang="en-US"> Discontinued Operations, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DiscontinuedOperationsPolicyTextBlock_lbl" xml:lang="en-US"> Discontinued Operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CompensationRelatedCostsPolicyTextBlock" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CompensationRelatedCostsPolicyTextBlock" xlink:to="us-gaap_CompensationRelatedCostsPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock_lbl" xml:lang="en-US"> Compensation Related Costs, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock_lbl" xml:lang="en-US"> Stock-based Compensation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US"> Use of Estimates, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US"> Use of Estimates </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestIncomeAndInterestExpenseDisclosureTextBlock" xlink:label="us-gaap_InterestIncomeAndInterestExpenseDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestIncomeAndInterestExpenseDisclosureTextBlock" xlink:to="us-gaap_InterestIncomeAndInterestExpenseDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestIncomeAndInterestExpenseDisclosureTextBlock_lbl" xml:lang="en-US"> Interest Income and Interest Expense Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InterestIncomeAndInterestExpenseDisclosureTextBlock_lbl" xml:lang="en-US"> Schedule of Interest Income and Interest Expense </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ComponentOfNetTradingRevenueTableTextBlock" xlink:label="kcg_ComponentOfNetTradingRevenueTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ComponentOfNetTradingRevenueTableTextBlock" xlink:to="kcg_ComponentOfNetTradingRevenueTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ComponentOfNetTradingRevenueTableTextBlock_lbl" xml:lang="en-US"> Component of Net Trading Revenue </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ComponentOfNetTradingRevenueTableTextBlock_lbl" xml:lang="en-US"> Component of Net Trading Revenue [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ComponentOfNetTradingRevenueTableTextBlock_lbl" xml:lang="en-US"> Component of Net Trading Revenue Includes Dividend Income and Expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:to="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" xml:lang="en-US"> Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" xml:lang="en-US"> Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:to="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_lbl" xml:lang="en-US"> Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_lbl" xml:lang="en-US"> Fair Value of Derivative Instruments Effect of Changes in Fair Value on Statements of Operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock" xlink:label="us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock" xlink:to="us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock_lbl" xml:lang="en-US"> Fair Value of Derivative Instruments Gain (Loss) Recognized </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock" xlink:label="us-gaap_ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock" xlink:to="us-gaap_ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock_lbl" xml:lang="en-US"> Schedule of Due to (from) Broker-Dealers and Clearing Organizations [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock_lbl" xml:lang="en-US"> Schedule of Amounts Receivable from and Payable to Brokers, Dealers and Clearing Organizations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTableTextBlock" xlink:label="us-gaap_ScheduleOfInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTableTextBlock" xlink:to="us-gaap_ScheduleOfInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTableTextBlock_lbl" xml:lang="en-US"> Schedule of Investments in and Advances to Affiliates, Schedule of Investments [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTableTextBlock_lbl" xml:lang="en-US"> Summary of Investments </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ScheduleOfIntangibleAssetsAndGoodwillNetOfAccumulatedAmortizationTableTextBlock" xlink:label="kcg_ScheduleOfIntangibleAssetsAndGoodwillNetOfAccumulatedAmortizationTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ScheduleOfIntangibleAssetsAndGoodwillNetOfAccumulatedAmortizationTableTextBlock" xlink:to="kcg_ScheduleOfIntangibleAssetsAndGoodwillNetOfAccumulatedAmortizationTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ScheduleOfIntangibleAssetsAndGoodwillNetOfAccumulatedAmortizationTableTextBlock_lbl" xml:lang="en-US"> Schedule of intangible assets and goodwill, net of accumulated Amortization [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ScheduleOfIntangibleAssetsAndGoodwillNetOfAccumulatedAmortizationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Intangible Assets and Goodwill, Net of Accumulated Amortization [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ScheduleOfIntangibleAssetsAndGoodwillNetOfAccumulatedAmortizationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Goodwill and Intangible Assets, Net of Accumulated Amortization </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ScheduleOfAmortizationExpenseTableTextBlock" xlink:label="kcg_ScheduleOfAmortizationExpenseTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ScheduleOfAmortizationExpenseTableTextBlock" xlink:to="kcg_ScheduleOfAmortizationExpenseTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ScheduleOfAmortizationExpenseTableTextBlock_lbl" xml:lang="en-US"> Schedule of Amortization Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ScheduleOfAmortizationExpenseTableTextBlock_lbl" xml:lang="en-US"> Schedule of Amortization Expense [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ScheduleOfAmortizationExpenseTableTextBlock_lbl" xml:lang="en-US"> Schedule of Amortization Expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfExpectedAmortizationExpenseTableTextBlock" xlink:label="us-gaap_ScheduleOfExpectedAmortizationExpenseTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfExpectedAmortizationExpenseTableTextBlock" xlink:to="us-gaap_ScheduleOfExpectedAmortizationExpenseTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfExpectedAmortizationExpenseTableTextBlock_lbl" xml:lang="en-US"> Schedule of Expected Amortization Expense [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfExpectedAmortizationExpenseTableTextBlock_lbl" xml:lang="en-US"> Schedule of Estimated Amortization Expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsByMajorClassTextBlock" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsByMajorClassTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsByMajorClassTextBlock" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsByMajorClassTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsByMajorClassTextBlock_lbl" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets by Major Class [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsByMajorClassTextBlock_lbl" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets, Net of Accumulated Amortization, by Segment and Type </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfDebtTableTextBlock" xlink:label="us-gaap_ScheduleOfDebtTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDebtTableTextBlock" xlink:to="us-gaap_ScheduleOfDebtTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDebtTableTextBlock_lbl" xml:lang="en-US"> Schedule of Debt [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfDebtTableTextBlock_lbl" xml:lang="en-US"> Summary Of Long-Term Debt </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ScheduleOfRecordedExpensesWithRespectToNoteTableTextBlock" xlink:label="kcg_ScheduleOfRecordedExpensesWithRespectToNoteTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ScheduleOfRecordedExpensesWithRespectToNoteTableTextBlock" xlink:to="kcg_ScheduleOfRecordedExpensesWithRespectToNoteTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ScheduleOfRecordedExpensesWithRespectToNoteTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Recorded Expenses With Respect To Note [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ScheduleOfRecordedExpensesWithRespectToNoteTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Recorded Expenses With Respect To Note [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ScheduleOfRecordedExpensesWithRespectToNoteTableTextBlock_lbl" xml:lang="en-US"> Schedule of Recorded Expenses with Respect to Notes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" xlink:label="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" xlink:to="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock_lbl" xml:lang="en-US"> Schedule of Comprehensive Income (Loss) [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock_lbl" xml:lang="en-US"> Schedule of Comprehensive Income </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" xlink:label="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" xlink:to="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock_lbl" xml:lang="en-US"> Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock_lbl" xml:lang="en-US"> Employee Compensation and Benefits, Restricted Awards </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_lbl" xml:lang="en-US"> Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_lbl" xml:lang="en-US"> Summary of Restricted Awards Activity </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsAndStockAppreciationRightsAwardActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsAndStockAppreciationRightsAwardActivityTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationStockOptionsAndStockAppreciationRightsAwardActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsAndStockAppreciationRightsAwardActivityTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsAndStockAppreciationRightsAwardActivityTableTextBlock_lbl" xml:lang="en-US"> Schedule of Share-based Compensation, Stock Options and Stock Appreciation Rights Award Activity [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsAndStockAppreciationRightsAwardActivityTableTextBlock_lbl" xml:lang="en-US"> Compensation Expense Relating to Stock Options </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xml:lang="en-US"> Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xml:lang="en-US"> Summary of Stock Option Activity </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Effective Income Tax Rate Reconciliation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Reconciliation Of Federal Statutory Income Tax Rate to the Company's Actual Income Tax Rate From Continuing Operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:to="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl" xml:lang="en-US"> Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl" xml:lang="en-US"> Schedule of Losses from Discontinued Operations Net of Tax </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock" xlink:label="kcg_ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock" xlink:to="kcg_ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Discontinued Operations Assets And Liabilities Recorded In Other Assets And Accrued Expenses And Other Liabilities Table Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Discontinued Operations Assets And Liabilities Recorded In Other Assets And Accrued Expenses And Other Liabilities Table Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedPeriodStartLabel" xlink:label="kcg_ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ScheduleOfDiscontinuedOperationsAssetsAndLiabilitiesRecordedInOtherAssetsAndAccruedExpensesAndOtherLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> Schedule of Discontinued Operations Assets and Liabilities Recorded in Other Assets and Accrued Expenses and Other Liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfCalculationOfNumeratorAndDenominatorInEarningsPerShareTableTextBlock" xlink:label="us-gaap_ScheduleOfCalculationOfNumeratorAndDenominatorInEarningsPerShareTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfCalculationOfNumeratorAndDenominatorInEarningsPerShareTableTextBlock" xlink:to="us-gaap_ScheduleOfCalculationOfNumeratorAndDenominatorInEarningsPerShareTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfCalculationOfNumeratorAndDenominatorInEarningsPerShareTableTextBlock_lbl" xml:lang="en-US"> Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfCalculationOfNumeratorAndDenominatorInEarningsPerShareTableTextBlock_lbl" xml:lang="en-US"> Schedule of Calculation of Numerator and Denominator in Earnings Per Share </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock" xlink:label="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock" xlink:to="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock_lbl" xml:lang="en-US"> Schedule of Future Minimum Lease Payments for Capital Leases [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock_lbl" xml:lang="en-US"> Schedule of Lease and Contract Obligations </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_FairValueOfAssetsOrLiabilityOnFutureContractTableTextBlock" xlink:label="kcg_FairValueOfAssetsOrLiabilityOnFutureContractTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_FairValueOfAssetsOrLiabilityOnFutureContractTableTextBlock" xlink:to="kcg_FairValueOfAssetsOrLiabilityOnFutureContractTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_FairValueOfAssetsOrLiabilityOnFutureContractTableTextBlock_lbl" xml:lang="en-US"> Fair Value of Assets Or Liability on Future Contract [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_FairValueOfAssetsOrLiabilityOnFutureContractTableTextBlock_lbl" xml:lang="en-US"> Fair Value of Assets Or Liability on Future Contract [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_FairValueOfAssetsOrLiabilityOnFutureContractTableTextBlock_lbl" xml:lang="en-US"> Fair Value of Assets or Liability on Future Contract </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfRealizedGainLossTableTextBlock" xlink:label="us-gaap_ScheduleOfRealizedGainLossTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRealizedGainLossTableTextBlock" xlink:to="us-gaap_ScheduleOfRealizedGainLossTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfRealizedGainLossTableTextBlock_lbl" xml:lang="en-US"> Schedule of Realized Gain (Loss) [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfRealizedGainLossTableTextBlock_lbl" xml:lang="en-US"> Schedule of Realized Gain (Loss) on Future Contracts </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_NumberOfOperatingSegment" xlink:label="kcg_NumberOfOperatingSegment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_NumberOfOperatingSegment" xlink:to="kcg_NumberOfOperatingSegment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_NumberOfOperatingSegment_lbl" xml:lang="en-US"> Number Of Operating Segment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_NumberOfOperatingSegment_lbl" xml:lang="en-US"> Number Of Operating Segment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_NumberOfOperatingSegment_lbl" xml:lang="en-US"> Number of operating segments </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_NumberOfCurrencyPairs" xlink:label="kcg_NumberOfCurrencyPairs"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_NumberOfCurrencyPairs" xlink:to="kcg_NumberOfCurrencyPairs_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_NumberOfCurrencyPairs_lbl" xml:lang="en-US"> Number of Currency Pairs </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_NumberOfCurrencyPairs_lbl" xml:lang="en-US"> Number of Currency Pairs </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_NumberOfCurrencyPairs_lbl" xml:lang="en-US"> Number of currency pairs </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:to="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_lbl" xml:lang="en-US"> Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis" xlink:label="us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis" xlink:to="us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis_lbl" xml:lang="en-US"> Derivative Instruments, Gain (Loss) by Income Statement Location [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeStatementAndOtherComprehensiveIncomeLocationDomain" xlink:label="us-gaap_IncomeStatementAndOtherComprehensiveIncomeLocationDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAndOtherComprehensiveIncomeLocationDomain" xlink:to="us-gaap_IncomeStatementAndOtherComprehensiveIncomeLocationDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementAndOtherComprehensiveIncomeLocationDomain_lbl" xml:lang="en-US"> Income Statement and Other Comprehensive Income (Loss) Location [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ForeignCurrencyGainLossMember" xlink:label="us-gaap_ForeignCurrencyGainLossMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCurrencyGainLossMember" xlink:to="us-gaap_ForeignCurrencyGainLossMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignCurrencyGainLossMember_lbl" xml:lang="en-US"> Losses Resulting From Foreign Currency Transactions [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InvestmentIncomeDividend" xlink:label="us-gaap_InvestmentIncomeDividend"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentIncomeDividend" xlink:to="us-gaap_InvestmentIncomeDividend_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentIncomeDividend_lbl" xml:lang="en-US"> Investment Income, Dividend </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InvestmentIncomeDividend_lbl" xml:lang="en-US"> Dividend Income </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DividendsCash" xlink:label="us-gaap_DividendsCash"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsCash" xlink:to="us-gaap_DividendsCash_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsCash_lbl" xml:lang="en-US"> Dividends, Cash </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DividendsCash_lbl" xml:lang="en-US"> Dividend Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DividendsCash_lbl" xml:lang="en-US"> Dividends, Cash, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DividendsCash_lbl" xml:lang="en-US"> Dividend Expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueLevel1ToLevel2TransfersAmount" xlink:label="us-gaap_FairValueLevel1ToLevel2TransfersAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueLevel1ToLevel2TransfersAmount" xlink:to="us-gaap_FairValueLevel1ToLevel2TransfersAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueLevel1ToLevel2TransfersAmount_lbl" xml:lang="en-US"> Fair Value, Level 1 to level 2 Transfers, Amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueLevel1ToLevel2TransfersAmount_lbl" xml:lang="en-US"> Transfers of financial instruments between levels </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NotionalAmountOfForeignCurrencyDerivatives" xlink:label="us-gaap_NotionalAmountOfForeignCurrencyDerivatives"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotionalAmountOfForeignCurrencyDerivatives" xlink:to="us-gaap_NotionalAmountOfForeignCurrencyDerivatives_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotionalAmountOfForeignCurrencyDerivatives_lbl" xml:lang="en-US"> Notional Amount of Foreign Currency Derivatives </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NotionalAmountOfForeignCurrencyDerivatives_lbl" xml:lang="en-US"> Notional value of foreign currency forward </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl" xml:lang="en-US"> Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xml:lang="en-US"> Fair Value, Hierarchy [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xml:lang="en-US"> Fair Value, Measurements, Fair Value Hierarchy [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel1Member" xlink:to="us-gaap_FairValueInputsLevel1Member_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xml:lang="en-US"> Level 1 [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel2Member" xlink:to="us-gaap_FairValueInputsLevel2Member_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xml:lang="en-US"> Level 2 [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel3Member" xlink:to="us-gaap_FairValueInputsLevel3Member_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xml:lang="en-US"> Level 3 [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="us-gaap_AssetsFairValueDisclosure"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsFairValueDisclosure" xlink:to="us-gaap_AssetsFairValueDisclosure_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xml:lang="en-US"> Assets, Fair Value Disclosure </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xml:lang="en-US"> Total fair value of financial instrument assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xml:lang="en-US"> Assets, Fair Value Disclosure, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="us-gaap_LiabilitiesFairValueDisclosure"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesFairValueDisclosure" xlink:to="us-gaap_LiabilitiesFairValueDisclosure_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xml:lang="en-US"> Liabilities, Fair Value Disclosure </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xml:lang="en-US"> Total fair value of financial instrument liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xml:lang="en-US"> Liabilities, Fair Value Disclosure, Total </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_DeferredCompensationInvestments" xlink:label="kcg_DeferredCompensationInvestments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_DeferredCompensationInvestments" xlink:to="kcg_DeferredCompensationInvestments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DeferredCompensationInvestments_lbl" xml:lang="en-US"> Deferred Compensation Investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DeferredCompensationInvestments_lbl" xml:lang="en-US"> Deferred Compensation Investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_DeferredCompensationInvestments_lbl" xml:lang="en-US"> Deferred compensation investments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:label="us-gaap_EquityMethodInvestmentsFairValueDisclosure"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:to="us-gaap_EquityMethodInvestmentsFairValueDisclosure_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentsFairValueDisclosure_lbl" xml:lang="en-US"> Equity Method Investments, Fair Value Disclosure </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EquityMethodInvestmentsFairValueDisclosure_lbl" xml:lang="en-US"> Equities </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LongAndShortListedEquityOptionContracts" xlink:label="kcg_LongAndShortListedEquityOptionContracts"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LongAndShortListedEquityOptionContracts" xlink:to="kcg_LongAndShortListedEquityOptionContracts_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LongAndShortListedEquityOptionContracts_lbl" xml:lang="en-US"> Long and short listed equity option contracts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LongAndShortListedEquityOptionContracts_lbl" xml:lang="en-US"> Long and Short Listed Equity Option Contracts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_LongAndShortListedEquityOptionContracts_lbl" xml:lang="en-US"> Long and short listed equity option contracts </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable" xlink:label="us-gaap_FairValueByBalanceSheetGroupingTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByBalanceSheetGroupingTable" xlink:to="us-gaap_FairValueByBalanceSheetGroupingTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueByBalanceSheetGroupingTable_lbl" xml:lang="en-US"> Fair Value, by Balance Sheet Grouping [Table] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LongListedEquityOptionContracts" xlink:label="kcg_LongListedEquityOptionContracts"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LongListedEquityOptionContracts" xlink:to="kcg_LongListedEquityOptionContracts_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LongListedEquityOptionContracts_lbl" xml:lang="en-US"> Long listed equity option contracts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LongListedEquityOptionContracts_lbl" xml:lang="en-US"> Long Listed Equity Option Contracts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_LongListedEquityOptionContracts_lbl" xml:lang="en-US"> Long listed equity option contracts </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ShortListedEquityOptionContracts" xlink:label="kcg_ShortListedEquityOptionContracts"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ShortListedEquityOptionContracts" xlink:to="kcg_ShortListedEquityOptionContracts_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ShortListedEquityOptionContracts_lbl" xml:lang="en-US"> Short listed equity option contracts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ShortListedEquityOptionContracts_lbl" xml:lang="en-US"> Short Listed Equity Option Contracts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ShortListedEquityOptionContracts_lbl" xml:lang="en-US"> Short listed equity option contracts </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetInvestmentIncome" xlink:label="us-gaap_NetInvestmentIncome"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetInvestmentIncome" xlink:to="us-gaap_NetInvestmentIncome_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetInvestmentIncome_lbl" xml:lang="en-US"> Net Investment Income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetInvestmentIncome_lbl" xml:lang="en-US"> Investment income (loss) and other, net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetInvestmentIncome_lbl" xml:lang="en-US"> Net Investment Income, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:to="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_lbl" xml:lang="en-US"> Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_lbl" xml:lang="en-US"> Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_lbl" xml:lang="en-US"> Derivative instruments not designated as hedging instruments, Gain (Loss) </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue" xlink:label="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue" xlink:to="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue_lbl" xml:lang="en-US"> Financial Instruments, Owned and Pledged as Collateral, at Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue_lbl" xml:lang="en-US"> Fair value of financial instruments received by collateral, permitted to deliver </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatCanBeResoldOrRepledged" xlink:label="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatCanBeResoldOrRepledged"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatCanBeResoldOrRepledged" xlink:to="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatCanBeResoldOrRepledged_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatCanBeResoldOrRepledged_lbl" xml:lang="en-US"> Fair Value of Securities Received as Collateral that Can be Resold or Repledged </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatCanBeResoldOrRepledged_lbl" xml:lang="en-US"> Fair value of financial instruments received by collateral, delivered or repledged </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged" xlink:label="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged" xlink:to="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged_lbl" xml:lang="en-US"> Fair Value of Securities Received as Collateral that Have Been Resold or Repledged </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged_lbl" xml:lang="en-US"> Fair value of financial instruments received by collateral, further repledged by receiving counterparty </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FinancialInstrumentsOwnedAndNotPledgedAtFairValue" xlink:label="us-gaap_FinancialInstrumentsOwnedAndNotPledgedAtFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancialInstrumentsOwnedAndNotPledgedAtFairValue" xlink:to="us-gaap_FinancialInstrumentsOwnedAndNotPledgedAtFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinancialInstrumentsOwnedAndNotPledgedAtFairValue_lbl" xml:lang="en-US"> Financial Instruments, Owned and Not Pledged, at Fair Value </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_PledgeAssetsOwnedToCounterpartiesIncludedInFinancialInstrumentsAtFairValue" xlink:label="kcg_PledgeAssetsOwnedToCounterpartiesIncludedInFinancialInstrumentsAtFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_PledgeAssetsOwnedToCounterpartiesIncludedInFinancialInstrumentsAtFairValue" xlink:to="kcg_PledgeAssetsOwnedToCounterpartiesIncludedInFinancialInstrumentsAtFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_PledgeAssetsOwnedToCounterpartiesIncludedInFinancialInstrumentsAtFairValue_lbl" xml:lang="en-US"> Pledge Assets Owned To Counterparties Included In Financial Instruments At Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_PledgeAssetsOwnedToCounterpartiesIncludedInFinancialInstrumentsAtFairValue_lbl" xml:lang="en-US"> Pledge Assets Owned To Counterparties Included In Financial Instruments At Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_PledgeAssetsOwnedToCounterpartiesIncludedInFinancialInstrumentsAtFairValue_lbl" xml:lang="en-US"> Pledge assets owned to counterparties right to deliver or repledge included in financial instruments at fair value </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_RepurchaseAgreementsAndOtherSecuredFinancingsMaturityPeriod" xlink:label="kcg_RepurchaseAgreementsAndOtherSecuredFinancingsMaturityPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_RepurchaseAgreementsAndOtherSecuredFinancingsMaturityPeriod" xlink:to="kcg_RepurchaseAgreementsAndOtherSecuredFinancingsMaturityPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_RepurchaseAgreementsAndOtherSecuredFinancingsMaturityPeriod_lbl" xml:lang="en-US"> Repurchase Agreements And Other Secured Financings Maturity Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_RepurchaseAgreementsAndOtherSecuredFinancingsMaturityPeriod_lbl" xml:lang="en-US"> Repurchase Agreements And Other Secured Financings Maturity Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_RepurchaseAgreementsAndOtherSecuredFinancingsMaturityPeriod_lbl" xml:lang="en-US"> Repurchase agreements and other secured financings, maturity (years) </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherReceivablesFromBrokerDealersAndClearingOrganizations" xlink:label="us-gaap_OtherReceivablesFromBrokerDealersAndClearingOrganizations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherReceivablesFromBrokerDealersAndClearingOrganizations" xlink:to="us-gaap_OtherReceivablesFromBrokerDealersAndClearingOrganizations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherReceivablesFromBrokerDealersAndClearingOrganizations_lbl" xml:lang="en-US"> Other Receivables from Broker-Dealers and Clearing Organizations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherReceivablesFromBrokerDealersAndClearingOrganizations_lbl" xml:lang="en-US"> Clearing organizations and other, Receivable </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SecuritiesFailedToDeliver" xlink:label="us-gaap_SecuritiesFailedToDeliver"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SecuritiesFailedToDeliver" xlink:to="us-gaap_SecuritiesFailedToDeliver_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SecuritiesFailedToDeliver_lbl" xml:lang="en-US"> Securities Failed-to-Deliver </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SecuritiesFailedToDeliver_lbl" xml:lang="en-US"> Securities failed to deliver </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherPayablesToBrokerDealersAndClearingOrganizations" xlink:label="us-gaap_OtherPayablesToBrokerDealersAndClearingOrganizations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherPayablesToBrokerDealersAndClearingOrganizations" xlink:to="us-gaap_OtherPayablesToBrokerDealersAndClearingOrganizations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherPayablesToBrokerDealersAndClearingOrganizations_lbl" xml:lang="en-US"> Other Payables to Broker-Dealers and Clearing Organizations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherPayablesToBrokerDealersAndClearingOrganizations_lbl" xml:lang="en-US"> Clearing organizations and other, Payable </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SecuritiesFailedToReceive" xlink:label="us-gaap_SecuritiesFailedToReceive"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SecuritiesFailedToReceive" xlink:to="us-gaap_SecuritiesFailedToReceive_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SecuritiesFailedToReceive_lbl" xml:lang="en-US"> Securities Failed-to-Receive </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SecuritiesFailedToReceive_lbl" xml:lang="en-US"> Securities failed to receive </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EquityMethodInvestmentAggregateCost" xlink:label="us-gaap_EquityMethodInvestmentAggregateCost"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentAggregateCost" xlink:to="us-gaap_EquityMethodInvestmentAggregateCost_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentAggregateCost_lbl" xml:lang="en-US"> Equity Method Investment, Aggregate Cost </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EquityMethodInvestmentAggregateCost_lbl" xml:lang="en-US"> Investments accounted for under the equity method </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_PrivateCompaniesInvestmentsLessThanTwentyPercentageEquityOwnershipHeldAtAdjustedCost" xlink:label="kcg_PrivateCompaniesInvestmentsLessThanTwentyPercentageEquityOwnershipHeldAtAdjustedCost"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_PrivateCompaniesInvestmentsLessThanTwentyPercentageEquityOwnershipHeldAtAdjustedCost" xlink:to="kcg_PrivateCompaniesInvestmentsLessThanTwentyPercentageEquityOwnershipHeldAtAdjustedCost_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_PrivateCompaniesInvestmentsLessThanTwentyPercentageEquityOwnershipHeldAtAdjustedCost_lbl" xml:lang="en-US"> Private Companies Investments Less Than twenty Percentage Equity Ownership Held at Adjusted Cost </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_PrivateCompaniesInvestmentsLessThanTwentyPercentageEquityOwnershipHeldAtAdjustedCost_lbl" xml:lang="en-US"> Private Companies Investments Less Than twenty Percentage Equity Ownership Held at Adjusted Cost </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_PrivateCompaniesInvestmentsLessThanTwentyPercentageEquityOwnershipHeldAtAdjustedCost_lbl" xml:lang="en-US"> Common stock of private companies representing less than 20% equity ownership held at adjusted cost </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_StrategicInvestments" xlink:label="kcg_StrategicInvestments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_StrategicInvestments" xlink:to="kcg_StrategicInvestments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_StrategicInvestments_lbl" xml:lang="en-US"> Strategic Investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_StrategicInvestments_lbl" xml:lang="en-US"> Strategic Investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="kcg_StrategicInvestments_lbl" xml:lang="en-US"> Total Strategic investments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredCompensationPlanAssets" xlink:label="us-gaap_DeferredCompensationPlanAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCompensationPlanAssets" xlink:to="us-gaap_DeferredCompensationPlanAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredCompensationPlanAssets_lbl" xml:lang="en-US"> Deferred Compensation Plan Assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredCompensationPlanAssets_lbl" xml:lang="en-US"> Deferred compensation investments </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_InvestmentInFunds" xlink:label="kcg_InvestmentInFunds"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_InvestmentInFunds" xlink:to="kcg_InvestmentInFunds_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_InvestmentInFunds_lbl" xml:lang="en-US"> Investment In Funds </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_InvestmentInFunds_lbl" xml:lang="en-US"> Investment In Funds </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_InvestmentInFunds_lbl" xml:lang="en-US"> Investment in Deephaven Funds </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EquityMethodInvestments" xlink:label="us-gaap_EquityMethodInvestments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestments" xlink:to="us-gaap_EquityMethodInvestments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestments_lbl" xml:lang="en-US"> Equity Method Investments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EquityMethodInvestments_lbl" xml:lang="en-US"> Included in investments accounted for under the equity method </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_WritedownOfAssetsAndLeaseLossAccrualAxis" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_WritedownOfAssetsAndLeaseLossAccrualAxis" xlink:to="kcg_WritedownOfAssetsAndLeaseLossAccrualAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualAxis_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Axis] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualAxis_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Axis] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_WritedownOfAssetsAndLeaseLossAccrualDomain" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_WritedownOfAssetsAndLeaseLossAccrualDomain" xlink:to="kcg_WritedownOfAssetsAndLeaseLossAccrualDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualDomain_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualDomain_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Domain] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_DiscontinuationOfLibertasTradeNameMember" xlink:label="kcg_DiscontinuationOfLibertasTradeNameMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_DiscontinuationOfLibertasTradeNameMember" xlink:to="kcg_DiscontinuationOfLibertasTradeNameMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DiscontinuationOfLibertasTradeNameMember_lbl" xml:lang="en-US"> Discontinuation Of The Libertas Trade Name [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DiscontinuationOfLibertasTradeNameMember_lbl" xml:lang="en-US"> Discontinuation Of The Libertas Trade Name [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="us-gaap_GoodwillImpairmentLoss"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillImpairmentLoss" xlink:to="us-gaap_GoodwillImpairmentLoss_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillImpairmentLoss_lbl" xml:lang="en-US"> Goodwill, Impairment Loss </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GoodwillImpairmentLoss_lbl" xml:lang="en-US"> Impairment of goodwill </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMinimum" xlink:label="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMinimum"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMinimum" xlink:to="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMinimum_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMinimum_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Useful Life, Minimum </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMinimum_lbl" xml:lang="en-US"> Amortization period, range minimum </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMaximum" xlink:label="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMaximum"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMaximum" xlink:to="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMaximum_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMaximum_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Useful Life, Maximum </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMaximum_lbl" xml:lang="en-US"> Amortization period, range maximum </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAverageUsefulLife" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAverageUsefulLife"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAverageUsefulLife" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAverageUsefulLife_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAverageUsefulLife_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Average Useful Life </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAverageUsefulLife_lbl" xml:lang="en-US"> Weighted average remaining life </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="us-gaap_ScheduleOfGoodwillTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfGoodwillTable" xlink:to="us-gaap_ScheduleOfGoodwillTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfGoodwillTable_lbl" xml:lang="en-US"> Schedule of Goodwill [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="us-gaap_StatementBusinessSegmentsAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementBusinessSegmentsAxis" xlink:to="us-gaap_StatementBusinessSegmentsAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementBusinessSegmentsAxis_lbl" xml:lang="en-US"> Statement, Business Segments [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SegmentDomain" xlink:label="us-gaap_SegmentDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentDomain" xlink:to="us-gaap_SegmentDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentDomain_lbl" xml:lang="en-US"> Segment [Domain] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_FiccMember" xlink:label="kcg_FiccMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_FiccMember" xlink:to="kcg_FiccMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_FiccMember_lbl" xml:lang="en-US"> FICC [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_FiccMember_lbl" xml:lang="en-US"> FICC [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_CorporateMember" xlink:label="kcg_CorporateMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_CorporateMember" xlink:to="kcg_CorporateMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_CorporateMember_lbl" xml:lang="en-US"> Corporate [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_CorporateMember_lbl" xml:lang="en-US"> Corporate [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_TotalMember" xlink:label="kcg_TotalMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_TotalMember" xlink:to="kcg_TotalMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_TotalMember_lbl" xml:lang="en-US"> Total [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_TotalMember_lbl" xml:lang="en-US"> Total [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xml:lang="en-US"> Business Acquisition [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xml:lang="en-US"> Business Acquisition, Acquiree [Domain] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_TrimarkBuisinessMember" xlink:label="kcg_TrimarkBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_TrimarkBuisinessMember" xlink:to="kcg_TrimarkBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_TrimarkBuisinessMember_lbl" xml:lang="en-US"> Trimark Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_TrimarkBuisinessMember_lbl" xml:lang="en-US"> Purchase of Trimark Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_TradetechBusinessMember" xlink:label="kcg_TradetechBusinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_TradetechBusinessMember" xlink:to="kcg_TradetechBusinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_TradetechBusinessMember_lbl" xml:lang="en-US"> Tradetech Business [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_TradetechBusinessMember_lbl" xml:lang="en-US"> Purchase of Tradetech Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_DonaldsonBusinessMember" xlink:label="kcg_DonaldsonBusinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_DonaldsonBusinessMember" xlink:to="kcg_DonaldsonBusinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DonaldsonBusinessMember_lbl" xml:lang="en-US"> Donaldson Business [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DonaldsonBusinessMember_lbl" xml:lang="en-US"> Purchase of Donaldson Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_KnightRoundtableEuropeMember" xlink:label="kcg_KnightRoundtableEuropeMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_KnightRoundtableEuropeMember" xlink:to="kcg_KnightRoundtableEuropeMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_KnightRoundtableEuropeMember_lbl" xml:lang="en-US"> Knight Roundtable Europe [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_KnightRoundtableEuropeMember_lbl" xml:lang="en-US"> Purchase of Remaining Shares in Knight Roundtable Europe [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_DirectTradingBuisinessMember" xlink:label="kcg_DirectTradingBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_DirectTradingBuisinessMember" xlink:to="kcg_DirectTradingBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DirectTradingBuisinessMember_lbl" xml:lang="en-US"> Direct Trading Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DirectTradingBuisinessMember_lbl" xml:lang="en-US"> Purchase of Direct Trading Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_EdgetradeBuisinessMember" xlink:label="kcg_EdgetradeBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_EdgetradeBuisinessMember" xlink:to="kcg_EdgetradeBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_EdgetradeBuisinessMember_lbl" xml:lang="en-US"> EdgeTrade Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_EdgetradeBuisinessMember_lbl" xml:lang="en-US"> Purchase of EdgeTrade Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_AstorBuisinessMember" xlink:label="kcg_AstorBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_AstorBuisinessMember" xlink:to="kcg_AstorBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_AstorBuisinessMember_lbl" xml:lang="en-US"> Astor Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_AstorBuisinessMember_lbl" xml:lang="en-US"> Purchase of Astor Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_KelloggDmmLmmBuisinessMember" xlink:label="kcg_KelloggDmmLmmBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_KelloggDmmLmmBuisinessMember" xlink:to="kcg_KelloggDmmLmmBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_KelloggDmmLmmBuisinessMember_lbl" xml:lang="en-US"> Kellogg DMM & LMM Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_KelloggDmmLmmBuisinessMember_lbl" xml:lang="en-US"> Purchase of Kellogg DMM & LMM Business Units [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_HotspotBuisinessMember" xlink:label="kcg_HotspotBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_HotspotBuisinessMember" xlink:to="kcg_HotspotBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_HotspotBuisinessMember_lbl" xml:lang="en-US"> Hotspot Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_HotspotBuisinessMember_lbl" xml:lang="en-US"> Purchase of Hotspot Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ValubondBuisinessMember" xlink:label="kcg_ValubondBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ValubondBuisinessMember" xlink:to="kcg_ValubondBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ValubondBuisinessMember_lbl" xml:lang="en-US"> ValuBond Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ValubondBuisinessMember_lbl" xml:lang="en-US"> Purchase of ValuBond Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LibertasBuisinessMember" xlink:label="kcg_LibertasBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LibertasBuisinessMember" xlink:to="kcg_LibertasBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LibertasBuisinessMember_lbl" xml:lang="en-US"> Libertas Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LibertasBuisinessMember_lbl" xml:lang="en-US"> Purchase of Libertas Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_UrbanBuisinessMember" xlink:label="kcg_UrbanBuisinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_UrbanBuisinessMember" xlink:to="kcg_UrbanBuisinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_UrbanBuisinessMember_lbl" xml:lang="en-US"> Urban Buisiness [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_UrbanBuisinessMember_lbl" xml:lang="en-US"> Purchase of Urban Business [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_OtherBusinessMember" xlink:label="kcg_OtherBusinessMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_OtherBusinessMember" xlink:to="kcg_OtherBusinessMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_OtherBusinessMember_lbl" xml:lang="en-US"> Other Business [member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_OtherBusinessMember_lbl" xml:lang="en-US"> Other Business [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount" xlink:label="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount" xlink:to="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount_lbl" xml:lang="en-US"> Business Acquisition, Purchase Price Allocation, Goodwill Amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount_lbl" xml:lang="en-US"> Goodwill </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount_lbl" xml:lang="en-US"> Business Acquisition, Purchase Price Allocation, Goodwill Amount, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl" xml:lang="en-US"> Indefinite-lived Intangible Assets by Major Class [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_lbl" xml:lang="en-US"> Indefinite-lived Intangible Assets, Major Class Name [Domain] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_CustomerAndBrokerRelationshipsMember" xlink:label="kcg_CustomerAndBrokerRelationshipsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_CustomerAndBrokerRelationshipsMember" xlink:to="kcg_CustomerAndBrokerRelationshipsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_CustomerAndBrokerRelationshipsMember_lbl" xml:lang="en-US"> Customer and Broker Relationships [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_CustomerAndBrokerRelationshipsMember_lbl" xml:lang="en-US"> Customer and Broker Relationships [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="us-gaap_TradeNamesMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradeNamesMember" xlink:to="us-gaap_TradeNamesMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TradeNamesMember_lbl" xml:lang="en-US"> Trade Names [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherIntangibleAssetsMember" xlink:label="us-gaap_OtherIntangibleAssetsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherIntangibleAssetsMember" xlink:to="us-gaap_OtherIntangibleAssetsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherIntangibleAssetsMember_lbl" xml:lang="en-US"> Other [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xml:lang="en-US"> Net carrying amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Net, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xml:lang="en-US"> Intangible Assets, Net carrying amount </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xml:lang="en-US"> Gross carrying amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Gross, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xml:lang="en-US"> Intangible assets, accumulated amortization </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xml:lang="en-US"> Accumulated amortization </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xml:lang="en-US"> Accumulated amortization </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="us-gaap_FiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:to="us-gaap_FiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Weighted-Average Useful Life </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US"> Weighted average remaining life </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Weighted-Average Useful Life, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US"> Amortization of Intangible Assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US"> Amortization Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US"> Amortization of Intangible Assets, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseRemainderOfFiscalYear" xlink:label="us-gaap_FutureAmortizationExpenseRemainderOfFiscalYear"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FutureAmortizationExpenseRemainderOfFiscalYear" xlink:to="us-gaap_FutureAmortizationExpenseRemainderOfFiscalYear_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FutureAmortizationExpenseRemainderOfFiscalYear_lbl" xml:lang="en-US"> Future Amortization Expense, Remainder of Fiscal Year </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FutureAmortizationExpenseRemainderOfFiscalYear_lbl" xml:lang="en-US"> Nine months ending December 31, 2011 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearOne" xlink:label="us-gaap_FutureAmortizationExpenseYearOne"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FutureAmortizationExpenseYearOne" xlink:to="us-gaap_FutureAmortizationExpenseYearOne_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FutureAmortizationExpenseYearOne_lbl" xml:lang="en-US"> Future Amortization Expense, Year One </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FutureAmortizationExpenseYearOne_lbl" xml:lang="en-US"> Year ended December 31, 2012 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearTwo" xlink:label="us-gaap_FutureAmortizationExpenseYearTwo"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FutureAmortizationExpenseYearTwo" xlink:to="us-gaap_FutureAmortizationExpenseYearTwo_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FutureAmortizationExpenseYearTwo_lbl" xml:lang="en-US"> Future Amortization Expense, Year Two </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FutureAmortizationExpenseYearTwo_lbl" xml:lang="en-US"> Year ended December 31, 2013 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearThree" xlink:label="us-gaap_FutureAmortizationExpenseYearThree"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FutureAmortizationExpenseYearThree" xlink:to="us-gaap_FutureAmortizationExpenseYearThree_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FutureAmortizationExpenseYearThree_lbl" xml:lang="en-US"> Future Amortization Expense, Year Three </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FutureAmortizationExpenseYearThree_lbl" xml:lang="en-US"> Year ended December 31, 2014 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearFour" xlink:label="us-gaap_FutureAmortizationExpenseYearFour"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FutureAmortizationExpenseYearFour" xlink:to="us-gaap_FutureAmortizationExpenseYearFour_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FutureAmortizationExpenseYearFour_lbl" xml:lang="en-US"> Future Amortization Expense, Year Four </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FutureAmortizationExpenseYearFour_lbl" xml:lang="en-US"> Year ended December 31, 2015 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearFive" xlink:label="us-gaap_FutureAmortizationExpenseYearFive"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FutureAmortizationExpenseYearFive" xlink:to="us-gaap_FutureAmortizationExpenseYearFive_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FutureAmortizationExpenseYearFive_lbl" xml:lang="en-US"> Future Amortization Expense, Year Five </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FutureAmortizationExpenseYearFive_lbl" xml:lang="en-US"> Thereafter through December 31, 2030 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:label="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Future Amortization Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense_lbl" xml:lang="en-US"> Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense_lbl" xml:lang="en-US"> Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityTable" xlink:label="us-gaap_LineOfCreditFacilityTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityTable" xlink:to="us-gaap_LineOfCreditFacilityTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityTable_lbl" xml:lang="en-US"> Line of Credit Facility [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityAxis" xlink:label="us-gaap_LineOfCreditFacilityAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityAxis" xlink:to="us-gaap_LineOfCreditFacilityAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityAxis_lbl" xml:lang="en-US"> Line of Credit Facility [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="us-gaap_LineOfCreditFacilityLenderDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityLenderDomain" xlink:to="us-gaap_LineOfCreditFacilityLenderDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityLenderDomain_lbl" xml:lang="en-US"> Line of Credit Facility, Lender [Domain] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_BorrowingBaseLoanMember" xlink:label="kcg_BorrowingBaseLoanMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_BorrowingBaseLoanMember" xlink:to="kcg_BorrowingBaseLoanMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_BorrowingBaseLoanMember_lbl" xml:lang="en-US"> Borrowing Base A Loan [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_BorrowingBaseLoanMember_lbl" xml:lang="en-US"> Borrowing Base A Loan [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_BorrowingBaseBLoanMember" xlink:label="kcg_BorrowingBaseBLoanMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_BorrowingBaseBLoanMember" xlink:to="kcg_BorrowingBaseBLoanMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_BorrowingBaseBLoanMember_lbl" xml:lang="en-US"> Borrowing Base B Loan [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_BorrowingBaseBLoanMember_lbl" xml:lang="en-US"> Borrowing Base B Loan [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ConvertibleSeniorSubordinatedNotesMember" xlink:label="kcg_ConvertibleSeniorSubordinatedNotesMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ConvertibleSeniorSubordinatedNotesMember" xlink:to="kcg_ConvertibleSeniorSubordinatedNotesMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ConvertibleSeniorSubordinatedNotesMember_lbl" xml:lang="en-US"> Convertible Senior Subordinated Notes [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ConvertibleSeniorSubordinatedNotesMember_lbl" xml:lang="en-US"> Convertible Senior Subordinated Notes [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LineOfCreditFacilityInterestRateComponentsAxis" xlink:label="kcg_LineOfCreditFacilityInterestRateComponentsAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LineOfCreditFacilityInterestRateComponentsAxis" xlink:to="kcg_LineOfCreditFacilityInterestRateComponentsAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LineOfCreditFacilityInterestRateComponentsAxis_lbl" xml:lang="en-US"> Line Of Credit Facility Interest Rate Components [Axis] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LineOfCreditFacilityInterestRateComponentsAxis_lbl" xml:lang="en-US"> Line Of Credit Facility Interest Rate Components [Axis] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LineOfCreditFacilityInterestRateComponentsDomain" xlink:label="kcg_LineOfCreditFacilityInterestRateComponentsDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LineOfCreditFacilityInterestRateComponentsDomain" xlink:to="kcg_LineOfCreditFacilityInterestRateComponentsDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LineOfCreditFacilityInterestRateComponentsDomain_lbl" xml:lang="en-US"> Line Of Credit Facility Interest Rate Components [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LineOfCreditFacilityInterestRateComponentsDomain_lbl" xml:lang="en-US"> Line Of Credit Facility Interest Rate Components [Domain] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LiborMember" xlink:label="kcg_LiborMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LiborMember" xlink:to="kcg_LiborMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LiborMember_lbl" xml:lang="en-US"> LIBOR [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LiborMember_lbl" xml:lang="en-US"> LIBOR [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_BaseRateMember" xlink:label="kcg_BaseRateMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_BaseRateMember" xlink:to="kcg_BaseRateMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_BaseRateMember_lbl" xml:lang="en-US"> Base Rate [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_BaseRateMember_lbl" xml:lang="en-US"> Base Rate [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RangeAxis" xlink:label="us-gaap_RangeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RangeAxis" xlink:to="us-gaap_RangeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RangeAxis_lbl" xml:lang="en-US"> Range [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RangeMember" xlink:label="us-gaap_RangeMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_RangeMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RangeMember_lbl" xml:lang="en-US"> Range [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MinimumMember" xlink:label="us-gaap_MinimumMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinimumMember" xlink:to="us-gaap_MinimumMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinimumMember_lbl" xml:lang="en-US"> Minimum [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MaximumMember" xlink:label="us-gaap_MaximumMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MaximumMember" xlink:to="us-gaap_MaximumMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MaximumMember_lbl" xml:lang="en-US"> Maximum [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeAxis" xlink:label="us-gaap_OptionIndexedToIssuersEquityTypeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OptionIndexedToIssuersEquityTypeAxis" xlink:to="us-gaap_OptionIndexedToIssuersEquityTypeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OptionIndexedToIssuersEquityTypeAxis_lbl" xml:lang="en-US"> Option Indexed to Issuer's Equity, Type [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain" xlink:label="us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OptionIndexedToIssuersEquityTypeDomain" xlink:to="us-gaap_OptionIndexedToIssuersEquityTypeDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OptionIndexedToIssuersEquityTypeDomain_lbl" xml:lang="en-US"> Option Indexed to Issuer's Equity, Type [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PurchasedCallOptionMember" xlink:label="us-gaap_PurchasedCallOptionMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PurchasedCallOptionMember" xlink:to="us-gaap_PurchasedCallOptionMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PurchasedCallOptionMember_lbl" xml:lang="en-US"> Purchased Call Options [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityInitiationDate" xlink:label="us-gaap_LineOfCreditFacilityInitiationDate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInitiationDate" xlink:to="us-gaap_LineOfCreditFacilityInitiationDate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityInitiationDate_lbl" xml:lang="en-US"> Line of Credit Facility, Initiation Date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCredit" xlink:label="us-gaap_LineOfCredit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCredit" xlink:to="us-gaap_LineOfCredit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCredit_lbl" xml:lang="en-US"> Credit facility </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LineOfCredit_lbl" xml:lang="en-US"> Long-term Line of Credit, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCredit_lbl" xml:lang="en-US"> Term Credit Agreement </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_BorrowingsTermLength" xlink:label="kcg_BorrowingsTermLength"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_BorrowingsTermLength" xlink:to="kcg_BorrowingsTermLength_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_BorrowingsTermLength_lbl" xml:lang="en-US"> Borrowings Term Length </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_BorrowingsTermLength_lbl" xml:lang="en-US"> Borrowings Term Length </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LineOfCreditFacilityInterestRate" xlink:label="kcg_LineOfCreditFacilityInterestRate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LineOfCreditFacilityInterestRate" xlink:to="kcg_LineOfCreditFacilityInterestRate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LineOfCreditFacilityInterestRate_lbl" xml:lang="en-US"> Line Of Credit Facility Interest Rate </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LineOfCreditFacilityInterestRate_lbl" xml:lang="en-US"> Line Of Credit Facility Interest Rate </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityDateOfFirstRequiredPayment" xlink:label="us-gaap_LineOfCreditFacilityDateOfFirstRequiredPayment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityDateOfFirstRequiredPayment" xlink:to="us-gaap_LineOfCreditFacilityDateOfFirstRequiredPayment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityDateOfFirstRequiredPayment_lbl" xml:lang="en-US"> Line of Credit Facility, Date of First Required Payment </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LineOfCreditFacilityPeriodPaymentFirstInstallment" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentFirstInstallment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LineOfCreditFacilityPeriodPaymentFirstInstallment" xlink:to="kcg_LineOfCreditFacilityPeriodPaymentFirstInstallment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentFirstInstallment_lbl" xml:lang="en-US"> Line Of Credit Facility Period Payment First Installment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentFirstInstallment_lbl" xml:lang="en-US"> Line Of Credit Facility Period Payment First Installment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentFirstInstallment_lbl" xml:lang="en-US"> Term loan, First installment </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LineOfCreditFacilityPeriodPaymentSecondInstallment" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentSecondInstallment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LineOfCreditFacilityPeriodPaymentSecondInstallment" xlink:to="kcg_LineOfCreditFacilityPeriodPaymentSecondInstallment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentSecondInstallment_lbl" xml:lang="en-US"> Line Of Credit Facility Period Payment Second Installment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentSecondInstallment_lbl" xml:lang="en-US"> Line Of Credit Facility Period Payment Second Installment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentSecondInstallment_lbl" xml:lang="en-US"> Term loan, Second Installment </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LineOfCreditFacilityPeriodPaymentFinalInstallment" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentFinalInstallment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LineOfCreditFacilityPeriodPaymentFinalInstallment" xlink:to="kcg_LineOfCreditFacilityPeriodPaymentFinalInstallment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentFinalInstallment_lbl" xml:lang="en-US"> Line Of Credit Facility Period Payment Final Installment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentFinalInstallment_lbl" xml:lang="en-US"> Line Of Credit Facility Period Payment Final Installment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_LineOfCreditFacilityPeriodPaymentFinalInstallment_lbl" xml:lang="en-US"> Term loan, Final installment </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LineOfCreditFacilityMarginInterestRate" xlink:label="kcg_LineOfCreditFacilityMarginInterestRate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LineOfCreditFacilityMarginInterestRate" xlink:to="kcg_LineOfCreditFacilityMarginInterestRate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LineOfCreditFacilityMarginInterestRate_lbl" xml:lang="en-US"> Line Of Credit Facility Margin Interest Rate </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LineOfCreditFacilityMarginInterestRate_lbl" xml:lang="en-US"> Line Of Credit Facility Margin Interest Rate </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityFrequencyOfCommitmentFeePayment" xlink:label="us-gaap_LineOfCreditFacilityFrequencyOfCommitmentFeePayment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityFrequencyOfCommitmentFeePayment" xlink:to="us-gaap_LineOfCreditFacilityFrequencyOfCommitmentFeePayment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityFrequencyOfCommitmentFeePayment_lbl" xml:lang="en-US"> Line of Credit Facility, Frequency of Commitment Fee Payment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:label="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:to="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_lbl" xml:lang="en-US"> Line of Credit Facility, Unused Capacity, Commitment Fee Percentage </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityCommitmentFeeAmount" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeeAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCommitmentFeeAmount" xlink:to="us-gaap_LineOfCreditFacilityCommitmentFeeAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeeAmount_lbl" xml:lang="en-US"> Line of Credit Facility, Commitment Fee Amount </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ConvertibleSubordinatedDebt" xlink:label="us-gaap_ConvertibleSubordinatedDebt"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertibleSubordinatedDebt" xlink:to="us-gaap_ConvertibleSubordinatedDebt_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConvertibleSubordinatedDebt_lbl" xml:lang="en-US"> Convertible Subordinated Debt </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConvertibleSubordinatedDebt_lbl" xml:lang="en-US"> Issue of Cash Convertible Senior Subordinated Notes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ConvertibleSubordinatedDebt_lbl" xml:lang="en-US"> Convertible Subordinated Debt, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:label="us-gaap_DebtInstrumentMaturityDate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDate" xlink:to="us-gaap_DebtInstrumentMaturityDate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US"> Debt Instrument, Maturity Date </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US"> Cash Convertible Senior Subordinated Notes due date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DistributionMadeToMemberOrLimitedPartnerShareDistributionDilutionPerShare" xlink:label="us-gaap_DistributionMadeToMemberOrLimitedPartnerShareDistributionDilutionPerShare"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DistributionMadeToMemberOrLimitedPartnerShareDistributionDilutionPerShare" xlink:to="us-gaap_DistributionMadeToMemberOrLimitedPartnerShareDistributionDilutionPerShare_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DistributionMadeToMemberOrLimitedPartnerShareDistributionDilutionPerShare_lbl" xml:lang="en-US"> Distribution Made to Member or Limited Partner, Share Distribution, Dilution Per Share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DistributionMadeToMemberOrLimitedPartnerShareDistributionDilutionPerShare_lbl" xml:lang="en-US"> Shareholder dilution up to a price per share </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SubordinatedBorrowingInterestRate" xlink:label="us-gaap_SubordinatedBorrowingInterestRate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubordinatedBorrowingInterestRate" xlink:to="us-gaap_SubordinatedBorrowingInterestRate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubordinatedBorrowingInterestRate_lbl" xml:lang="en-US"> Subordinated Borrowing, Interest Rate </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubordinatedBorrowingInterestRate_lbl" xml:lang="en-US"> Notes bear interest rate per year </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentMaturityDateRangeStart" xlink:label="us-gaap_DebtInstrumentMaturityDateRangeStart"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDateRangeStart" xlink:to="us-gaap_DebtInstrumentMaturityDateRangeStart_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentMaturityDateRangeStart_lbl" xml:lang="en-US"> Debt Instrument, Maturity Date Range, Start </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentMaturityDateRangeStart_lbl" xml:lang="en-US"> Date of commencing of notes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentMaturityDateRangeEnd" xlink:label="us-gaap_DebtInstrumentMaturityDateRangeEnd"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDateRangeEnd" xlink:to="us-gaap_DebtInstrumentMaturityDateRangeEnd_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentMaturityDateRangeEnd_lbl" xml:lang="en-US"> Debt Instrument, Maturity Date Range, End </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentMaturityDateRangeEnd_lbl" xml:lang="en-US"> Date of mature of notes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:to="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl" xml:lang="en-US"> Amortization of Financing Costs and Discounts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl" xml:lang="en-US"> Recognized original issue discount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl" xml:lang="en-US"> Amortization of Financing Costs and Discounts, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:to="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xml:lang="en-US"> Debt Instrument, Interest Rate, Effective Percentage </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xml:lang="en-US"> Effective annual interest rate of notes </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_NotesConvertibleBasedOnInitialConversionRateOfShares" xlink:label="kcg_NotesConvertibleBasedOnInitialConversionRateOfShares"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_NotesConvertibleBasedOnInitialConversionRateOfShares" xlink:to="kcg_NotesConvertibleBasedOnInitialConversionRateOfShares_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_NotesConvertibleBasedOnInitialConversionRateOfShares_lbl" xml:lang="en-US"> Notes Convertible Based On Initial Conversion Rate Of Shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_NotesConvertibleBasedOnInitialConversionRateOfShares_lbl" xml:lang="en-US"> Notes Convertible Based On Initial Conversion Rate Of Shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_NotesConvertibleBasedOnInitialConversionRateOfShares_lbl" xml:lang="en-US"> Notes convertible based on initial conversion rate of shares </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xml:lang="en-US"> Long-term Debt, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xml:lang="en-US"> Class A common stock per principal amount of notes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:to="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl" xml:lang="en-US"> Debt Instrument, Convertible, Conversion Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl" xml:lang="en-US"> Initial conversion price per share </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_InitialConversionPremiumOverClosingSale" xlink:label="kcg_InitialConversionPremiumOverClosingSale"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_InitialConversionPremiumOverClosingSale" xlink:to="kcg_InitialConversionPremiumOverClosingSale_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_InitialConversionPremiumOverClosingSale_lbl" xml:lang="en-US"> Initial Conversion Premium Over Closing Sale </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_InitialConversionPremiumOverClosingSale_lbl" xml:lang="en-US"> Initial Conversion Premium Over Closing Sale </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_InitialConversionPremiumOverClosingSale_lbl" xml:lang="en-US"> Initial conversion premium over closing sale </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ClosingSalePriceOfCommonStockOnNasdaq" xlink:label="kcg_ClosingSalePriceOfCommonStockOnNasdaq"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ClosingSalePriceOfCommonStockOnNasdaq" xlink:to="kcg_ClosingSalePriceOfCommonStockOnNasdaq_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ClosingSalePriceOfCommonStockOnNasdaq_lbl" xml:lang="en-US"> Closing Sale Price Of Common Stock on NASDAQ </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ClosingSalePriceOfCommonStockOnNasdaq_lbl" xml:lang="en-US"> Closing Sale Price Of Common Stock on NASDAQ </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ClosingSalePriceOfCommonStockOnNasdaq_lbl" xml:lang="en-US"> Closing sale price of common stock on NASDAQ </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_PercentageOfPriceEqualToPrincipalAmountOfNotes" xlink:label="kcg_PercentageOfPriceEqualToPrincipalAmountOfNotes"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_PercentageOfPriceEqualToPrincipalAmountOfNotes" xlink:to="kcg_PercentageOfPriceEqualToPrincipalAmountOfNotes_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_PercentageOfPriceEqualToPrincipalAmountOfNotes_lbl" xml:lang="en-US"> Percentage Of Price Equal To Principal Amount Of Notes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_PercentageOfPriceEqualToPrincipalAmountOfNotes_lbl" xml:lang="en-US"> Percentage Of Price Equal To Principal Amount Of Notes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_PercentageOfPriceEqualToPrincipalAmountOfNotes_lbl" xml:lang="en-US"> Percentage of price equal to principal amount of notes </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_AmountPaidToEnterIntoPrivatelyNegotiatedCashConvertibleNoteHedgeTransactions" xlink:label="kcg_AmountPaidToEnterIntoPrivatelyNegotiatedCashConvertibleNoteHedgeTransactions"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_AmountPaidToEnterIntoPrivatelyNegotiatedCashConvertibleNoteHedgeTransactions" xlink:to="kcg_AmountPaidToEnterIntoPrivatelyNegotiatedCashConvertibleNoteHedgeTransactions_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_AmountPaidToEnterIntoPrivatelyNegotiatedCashConvertibleNoteHedgeTransactions_lbl" xml:lang="en-US"> Amount Paid To Enter Into Privately Negotiated Cash Convertible Note Hedge Transactions </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_AmountPaidToEnterIntoPrivatelyNegotiatedCashConvertibleNoteHedgeTransactions_lbl" xml:lang="en-US"> Amount Paid To Enter Into Privately Negotiated Cash Convertible Note Hedge Transactions </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_AmountPaidToEnterIntoPrivatelyNegotiatedCashConvertibleNoteHedgeTransactions_lbl" xml:lang="en-US"> Amount paid to enter into privately negotiated cash convertible note hedge transactions </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_NumberOfSharesSubjectToAdjustmentOfCommonStock" xlink:label="kcg_NumberOfSharesSubjectToAdjustmentOfCommonStock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_NumberOfSharesSubjectToAdjustmentOfCommonStock" xlink:to="kcg_NumberOfSharesSubjectToAdjustmentOfCommonStock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_NumberOfSharesSubjectToAdjustmentOfCommonStock_lbl" xml:lang="en-US"> Number of Shares Subject To Adjustment Of Common Stock </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_NumberOfSharesSubjectToAdjustmentOfCommonStock_lbl" xml:lang="en-US"> Number of Shares Subject To Adjustment Of Common Stock </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_NumberOfSharesSubjectToAdjustmentOfCommonStock_lbl" xml:lang="en-US"> Number of shares subject to adjustment of common stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DerivativePriceRiskOptionStrikePrice" xlink:label="us-gaap_DerivativePriceRiskOptionStrikePrice"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativePriceRiskOptionStrikePrice" xlink:to="us-gaap_DerivativePriceRiskOptionStrikePrice_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativePriceRiskOptionStrikePrice_lbl" xml:lang="en-US"> Derivative, Price Risk Option Strike Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativePriceRiskOptionStrikePrice_lbl" xml:lang="en-US"> Common stock strike price </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockPricePerShare" xlink:to="us-gaap_SaleOfStockPricePerShare_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xml:lang="en-US"> Sale of Stock, Price Per Share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xml:lang="en-US"> Common stock subject to adjustments strike price per share </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_PercentageOfCommonStockSubjectToAdjustmentOfPremiumOverClosingPrice" xlink:label="kcg_PercentageOfCommonStockSubjectToAdjustmentOfPremiumOverClosingPrice"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_PercentageOfCommonStockSubjectToAdjustmentOfPremiumOverClosingPrice" xlink:to="kcg_PercentageOfCommonStockSubjectToAdjustmentOfPremiumOverClosingPrice_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_PercentageOfCommonStockSubjectToAdjustmentOfPremiumOverClosingPrice_lbl" xml:lang="en-US"> Percentage Of Common Stock Subject To Adjustment Of Premium Over Closing Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_PercentageOfCommonStockSubjectToAdjustmentOfPremiumOverClosingPrice_lbl" xml:lang="en-US"> Percentage Of Common Stock Subject To Adjustment Of Premium Over Closing Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_PercentageOfCommonStockSubjectToAdjustmentOfPremiumOverClosingPrice_lbl" xml:lang="en-US"> Percentage of common stock subject to adjustment of premium over closing price </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability" xlink:to="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_lbl" xml:lang="en-US"> Embedded Derivative, Fair Value of Embedded Derivative Liability </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_lbl" xml:lang="en-US"> Initial valuation of embedded conversion derivative </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeNet" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeNet" xlink:to="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeNet_lbl" xml:lang="en-US"> Embedded Derivative, Fair Value of Embedded Derivative, Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeNet_lbl" xml:lang="en-US"> Fair value of the embedded conversion derivative </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeNet_lbl" xml:lang="en-US"> Embedded Derivative, Fair Value of Embedded Derivative, Net, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDebtIssuanceCosts" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xml:lang="en-US"> Payments of Debt Issuance Costs </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xml:lang="en-US"> Issuance costs of notes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentDecreaseRepayments" xlink:label="us-gaap_DebtInstrumentDecreaseRepayments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentDecreaseRepayments" xlink:to="us-gaap_DebtInstrumentDecreaseRepayments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentDecreaseRepayments_lbl" xml:lang="en-US"> Debt Instrument, Decrease, Repayments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentDecreaseRepayments_lbl" xml:lang="en-US"> Repaid notes outstanding under credit agreement </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RepurchaseAgreementsInterestExpenseAmount" xlink:label="us-gaap_RepurchaseAgreementsInterestExpenseAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepurchaseAgreementsInterestExpenseAmount" xlink:to="us-gaap_RepurchaseAgreementsInterestExpenseAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepurchaseAgreementsInterestExpenseAmount_lbl" xml:lang="en-US"> Repurchase Agreements, Interest Expense Amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RepurchaseAgreementsInterestExpenseAmount_lbl" xml:lang="en-US"> Interest expenses relating to the credit agreement </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ConvertibleDebt" xlink:label="us-gaap_ConvertibleDebt"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertibleDebt" xlink:to="us-gaap_ConvertibleDebt_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConvertibleDebt_lbl" xml:lang="en-US"> Convertible Debt </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ConvertibleDebt_lbl" xml:lang="en-US"> Convertible Debt, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ConvertibleDebt_lbl" xml:lang="en-US"> Convertible Notes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestExpenseSubordinatedNotesAndDebentures" xlink:label="us-gaap_InterestExpenseSubordinatedNotesAndDebentures"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpenseSubordinatedNotesAndDebentures" xlink:to="us-gaap_InterestExpenseSubordinatedNotesAndDebentures_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpenseSubordinatedNotesAndDebentures_lbl" xml:lang="en-US"> Interest Expense, Subordinated Notes and Debentures </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestExpenseSubordinatedNotesAndDebentures_lbl" xml:lang="en-US"> Interest expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost" xlink:label="us-gaap_WriteOffOfDeferredDebtIssuanceCost"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WriteOffOfDeferredDebtIssuanceCost" xlink:to="us-gaap_WriteOffOfDeferredDebtIssuanceCost_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WriteOffOfDeferredDebtIssuanceCost_lbl" xml:lang="en-US"> Write off of Deferred Debt Issuance Cost </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WriteOffOfDeferredDebtIssuanceCost_lbl" xml:lang="en-US"> Amortization of debt issuance cost </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_NotesRelatedExpenses" xlink:label="kcg_NotesRelatedExpenses"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_NotesRelatedExpenses" xlink:to="kcg_NotesRelatedExpenses_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_NotesRelatedExpenses_lbl" xml:lang="en-US"> Notes Related Expenses </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_NotesRelatedExpenses_lbl" xml:lang="en-US"> Notes Related Expenses </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="kcg_NotesRelatedExpenses_lbl" xml:lang="en-US"> Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax" xlink:to="us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax_lbl" xml:lang="en-US"> Other Comprehensive Income, Foreign Currency Translation Adjustment, Tax, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax_lbl" xml:lang="en-US"> Other comprehensive income (loss): Cumulative translation adjustment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax_lbl" xml:lang="en-US"> Other Comprehensive Income, Foreign Currency Translation Adjustment, Tax, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xml:lang="en-US"> Comprehensive Income (Loss), Net of Tax, Attributable to Parent </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xml:lang="en-US"> Comprehensive income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xml:lang="en-US"> Comprehensive income </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xml:lang="en-US"> Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardAwardTypeAndPlanNameAxis" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardAwardTypeAndPlanNameAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardAwardTypeAndPlanNameAxis" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardAwardTypeAndPlanNameAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardAwardTypeAndPlanNameAxis_lbl" xml:lang="en-US"> Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Award Type and Plan Name [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xml:lang="en-US"> Share-based Compensation Arrangements by Share-based Payment Award, Award Type and Plan Name [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="us-gaap_RestrictedStockMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockMember" xlink:to="us-gaap_RestrictedStockMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockMember_lbl" xml:lang="en-US"> Restricted Stock [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockOptionsMember" xlink:label="us-gaap_StockOptionsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockOptionsMember" xlink:to="us-gaap_StockOptionsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockOptionsMember_lbl" xml:lang="en-US"> Stock Options [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod_lbl" xml:lang="en-US"> Vesting period of restricted awards, years </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl" xml:lang="en-US"> Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl" xml:lang="en-US"> Issuance of restricted shares, during the period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl" xml:lang="en-US"> Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures, Total </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ShareBasedCompensationUnvestedRestrictedAwardsOutstandingUnamortized" xlink:label="kcg_ShareBasedCompensationUnvestedRestrictedAwardsOutstandingUnamortized"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ShareBasedCompensationUnvestedRestrictedAwardsOutstandingUnamortized" xlink:to="kcg_ShareBasedCompensationUnvestedRestrictedAwardsOutstandingUnamortized_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ShareBasedCompensationUnvestedRestrictedAwardsOutstandingUnamortized_lbl" xml:lang="en-US"> Share Based Compensation, Unvested Restricted Awards Outstanding Unamortized </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ShareBasedCompensationUnvestedRestrictedAwardsOutstandingUnamortized_lbl" xml:lang="en-US"> Share Based Compensation, Unvested Restricted Awards Outstanding Unamortized </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ShareBasedCompensationUnvestedRestrictedAwardsOutstandingUnamortized_lbl" xml:lang="en-US"> Unrecognized compensation related to restricted awards outstanding </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_CostOfUnvestedAwardsExpectedToBeRecognizedOverWeightedAverageLife" xlink:label="kcg_CostOfUnvestedAwardsExpectedToBeRecognizedOverWeightedAverageLife"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_CostOfUnvestedAwardsExpectedToBeRecognizedOverWeightedAverageLife" xlink:to="kcg_CostOfUnvestedAwardsExpectedToBeRecognizedOverWeightedAverageLife_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_CostOfUnvestedAwardsExpectedToBeRecognizedOverWeightedAverageLife_lbl" xml:lang="en-US"> Cost of unvested awards expected to be recognized over a weighted average life </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_CostOfUnvestedAwardsExpectedToBeRecognizedOverWeightedAverageLife_lbl" xml:lang="en-US"> Cost Of Unvested Awards Expected To Be Recognized Over a Weighted Average Life </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_CostOfUnvestedAwardsExpectedToBeRecognizedOverWeightedAverageLife_lbl" xml:lang="en-US"> Cost of unvested awards expected to be recognized over a weighted average life, years </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_lbl" xml:lang="en-US"> Number of stock options, Granted at market value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted-average fair value of the stock options granted </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RestrictedStockExpense" xlink:label="us-gaap_RestrictedStockExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockExpense" xlink:to="us-gaap_RestrictedStockExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockExpense_lbl" xml:lang="en-US"> Restricted Stock or Unit Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RestrictedStockExpense_lbl" xml:lang="en-US"> Stock award compensation expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RestrictedStockExpense_lbl" xml:lang="en-US"> Stock option compensation expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_lbl" xml:lang="en-US"> Employee Service Share-based Compensation, Tax Benefit from Compensation Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_lbl" xml:lang="en-US"> Income tax benefit </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockUnitsRSUMember" xlink:to="us-gaap_RestrictedStockUnitsRSUMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xml:lang="en-US"> Restricted Stock Units (RSUs) [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US"> Number of Shares, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US"> Number of Shares, Beginning Balance </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US"> Number of Shares, Granted </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xml:lang="en-US"> Number of Shares, Vested </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xml:lang="en-US"> Number of Shares, Vested </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US"> Number of Shares, Forfeited </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US"> Number of Shares, Forfeited </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted-Average Grant date Fair Value, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted-Average Grant date Fair Value, Beginning Balance </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted-Average Grant date Fair Value, Granted </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted-Average Grant date Fair Value, Vested </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodWeightedAverageGrantDateFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodWeightedAverageGrantDateFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period, Weighted Average Grant Date Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted-Average Grant date Fair Value, Forfeited </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockOptionPlanExpense" xlink:label="us-gaap_StockOptionPlanExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockOptionPlanExpense" xlink:to="us-gaap_StockOptionPlanExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockOptionPlanExpense_lbl" xml:lang="en-US"> Stock or Unit Option Plan Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockOptionPlanExpense_lbl" xml:lang="en-US"> Stock award compensation expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockOptionPlanExpense_lbl" xml:lang="en-US"> Stock option compensation expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US"> Number of Stock Options, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US"> Number of Stock Options, Beginning Balance </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xml:lang="en-US"> Stock options exercised, shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xml:lang="en-US"> Number of Stock Options, Exercised </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xml:lang="en-US"> Number of Stock Options, Exercised </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_lbl" xml:lang="en-US"> Number of Stock Options, Forfeited or expired </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_lbl" xml:lang="en-US"> Number of Stock Options, Forfeited or expired </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xml:lang="en-US"> Number of Stock Options, Exercisable at June 30, 2011 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted-Average Exercise Price, Ending Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted-Average Exercise Price, Beginning Balance </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted-Average Exercise Price, Exercised </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted-Average Exercise Price, Forfeited or expired </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted-Average Exercise Price, Exercisable at June 30, 2011 </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForFutureGrantsInPeriod" xlink:label="kcg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForFutureGrantsInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForFutureGrantsInPeriod" xlink:to="kcg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForFutureGrantsInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForFutureGrantsInPeriod_lbl" xml:lang="en-US"> Share based compensation arrangement by share based payment award options for future grants in period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForFutureGrantsInPeriod_lbl" xml:lang="en-US"> Share Based Compensation Arrangement By Share Based Payment Award Options For Future Grants In Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForFutureGrantsInPeriod_lbl" xml:lang="en-US"> Available for future grants at March 31, 2011 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xml:lang="en-US"> U.S. federal statutory income tax rate </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, State and Local Income Taxes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xml:lang="en-US"> U.S. state and local income taxes, net of U.S. federal income tax effect </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_lbl" xml:lang="en-US"> Nondeductible charges and other, net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_lbl" xml:lang="en-US"> Nondeductible charges and other, net </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xml:lang="en-US"> Effective Income Tax Rate, Continuing Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xml:lang="en-US"> Actual income tax rate </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xml:lang="en-US"> Actual income tax rate </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_WritedownOfAssetsAndLeaseLossAccrualTable" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_WritedownOfAssetsAndLeaseLossAccrualTable" xlink:to="kcg_WritedownOfAssetsAndLeaseLossAccrualTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualTable_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Table] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_WritedownOfAssetsAndLeaseLossAccrualTable_lbl" xml:lang="en-US"> Writedown Of Assets And Lease Loss Accrual [Table] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ExcessRealEstateCapacityMember" xlink:label="kcg_ExcessRealEstateCapacityMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ExcessRealEstateCapacityMember" xlink:to="kcg_ExcessRealEstateCapacityMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ExcessRealEstateCapacityMember_lbl" xml:lang="en-US"> Excess Real Estate Capacity [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ExcessRealEstateCapacityMember_lbl" xml:lang="en-US"> Excess Real Estate Capacity [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_lbl" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Revenue </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_lbl" xml:lang="en-US"> Revenues </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_lbl" xml:lang="en-US"> Revenues </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax" xlink:to="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_lbl" xml:lang="en-US"> Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_lbl" xml:lang="en-US"> Pre-tax gain (loss) from discontinued operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_lbl" xml:lang="en-US"> Pre-tax gain (loss) from discontinued operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation" xlink:label="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation" xlink:to="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_lbl" xml:lang="en-US"> Discontinued Operation, Tax Effect of Discontinued Operation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_lbl" xml:lang="en-US"> Income tax expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_lbl" xml:lang="en-US"> Discontinued Operation, Tax Effect of Discontinued Operation, Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents_lbl" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents_lbl" xml:lang="en-US"> Cash and cash equivalents </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_DeferredCompensationAndOtherAssetsRelatedToDiscontinuedOperations" xlink:label="kcg_DeferredCompensationAndOtherAssetsRelatedToDiscontinuedOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_DeferredCompensationAndOtherAssetsRelatedToDiscontinuedOperations" xlink:to="kcg_DeferredCompensationAndOtherAssetsRelatedToDiscontinuedOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DeferredCompensationAndOtherAssetsRelatedToDiscontinuedOperations_lbl" xml:lang="en-US"> Deferred Compensation And Other Assets Related To Discontinued Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DeferredCompensationAndOtherAssetsRelatedToDiscontinuedOperations_lbl" xml:lang="en-US"> Deferred Compensation And Other Assets Related To Discontinued Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_DeferredCompensationAndOtherAssetsRelatedToDiscontinuedOperations_lbl" xml:lang="en-US"> Deferred compensation and other assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl" xml:lang="en-US"> Assets of Disposal Group, Including Discontinued Operation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl" xml:lang="en-US"> Total assets </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_AccruedCompensationExpenseRelatedToDiscontinuedOperations" xlink:label="kcg_AccruedCompensationExpenseRelatedToDiscontinuedOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_AccruedCompensationExpenseRelatedToDiscontinuedOperations" xlink:to="kcg_AccruedCompensationExpenseRelatedToDiscontinuedOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_AccruedCompensationExpenseRelatedToDiscontinuedOperations_lbl" xml:lang="en-US"> Accrued Compensation Expense Related To Discontinued Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_AccruedCompensationExpenseRelatedToDiscontinuedOperations_lbl" xml:lang="en-US"> Accrued Compensation Expense Related To Discontinued Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_AccruedCompensationExpenseRelatedToDiscontinuedOperations_lbl" xml:lang="en-US"> Accrued compensation expense </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_AccruedExpensesAndOtherLiabilitiesRelatedToDiscontinuedOperation" xlink:label="kcg_AccruedExpensesAndOtherLiabilitiesRelatedToDiscontinuedOperation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_AccruedExpensesAndOtherLiabilitiesRelatedToDiscontinuedOperation" xlink:to="kcg_AccruedExpensesAndOtherLiabilitiesRelatedToDiscontinuedOperation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_AccruedExpensesAndOtherLiabilitiesRelatedToDiscontinuedOperation_lbl" xml:lang="en-US"> Accrued Expenses And Other Liabilities Related To Discontinued Operation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_AccruedExpensesAndOtherLiabilitiesRelatedToDiscontinuedOperation_lbl" xml:lang="en-US"> Accrued Expenses And Other Liabilities Related To Discontinued Operation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_AccruedExpensesAndOtherLiabilitiesRelatedToDiscontinuedOperation_lbl" xml:lang="en-US"> Accrued expenses and other liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_lbl" xml:lang="en-US"> Liabilities of Disposal Group, Including Discontinued Operation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_lbl" xml:lang="en-US"> Total liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xml:lang="en-US"> Options excluded </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_EffectOfDilutiveStockBasedAwardsNetIncome" xlink:label="kcg_EffectOfDilutiveStockBasedAwardsNetIncome"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_EffectOfDilutiveStockBasedAwardsNetIncome" xlink:to="kcg_EffectOfDilutiveStockBasedAwardsNetIncome_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_EffectOfDilutiveStockBasedAwardsNetIncome_lbl" xml:lang="en-US"> Effect of dilutive stock based awards Net income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_EffectOfDilutiveStockBasedAwardsNetIncome_lbl" xml:lang="en-US"> Effect of dilutive stock based awards Net income </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLossAttributableToParentDiluted" xlink:label="us-gaap_NetIncomeLossAttributableToParentDiluted"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAttributableToParentDiluted" xlink:to="us-gaap_NetIncomeLossAttributableToParentDiluted_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLossAttributableToParentDiluted_lbl" xml:lang="en-US"> Net Income (Loss) Attributable to Parent, Diluted </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLossAttributableToParentDiluted_lbl" xml:lang="en-US"> Net income used in diluted calculations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLossAttributableToParentDiluted_lbl" xml:lang="en-US"> Net Income (Loss) Attributable to Parent, Diluted, Total </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_EffectOfDilutiveStockBasedAwardsShares" xlink:label="kcg_EffectOfDilutiveStockBasedAwardsShares"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_EffectOfDilutiveStockBasedAwardsShares" xlink:to="kcg_EffectOfDilutiveStockBasedAwardsShares_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_EffectOfDilutiveStockBasedAwardsShares_lbl" xml:lang="en-US"> Effect of dilutive stock based awards </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_EffectOfDilutiveStockBasedAwardsShares_lbl" xml:lang="en-US"> Effect of dilutive stock based awards shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_EffectOfDilutiveStockBasedAwardsShares_lbl" xml:lang="en-US"> Effect of dilutive stock based awards shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="kcg_EffectOfDilutiveStockBasedAwardsShares_lbl" xml:lang="en-US"> Effect of dilutive stock based awards shares </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_StatedMinimumPercentageOfTotalUsEquityDollerValueTradedForSignificantClientConsideration" xlink:label="kcg_StatedMinimumPercentageOfTotalUsEquityDollerValueTradedForSignificantClientConsideration"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_StatedMinimumPercentageOfTotalUsEquityDollerValueTradedForSignificantClientConsideration" xlink:to="kcg_StatedMinimumPercentageOfTotalUsEquityDollerValueTradedForSignificantClientConsideration_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_StatedMinimumPercentageOfTotalUsEquityDollerValueTradedForSignificantClientConsideration_lbl" xml:lang="en-US"> Stated Minimum Percentage of Total US Equity Doller Value Traded for Significant Client Consideration </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_StatedMinimumPercentageOfTotalUsEquityDollerValueTradedForSignificantClientConsideration_lbl" xml:lang="en-US"> Stated Minimum Percentage of Total US Equity Doller Value Traded for Significant Client Consideration </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_StatedMinimumPercentageOfTotalUsEquityDollerValueTradedForSignificantClientConsideration_lbl" xml:lang="en-US"> Percentage of dollar value traded </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_NumberOfSignificantClients" xlink:label="kcg_NumberOfSignificantClients"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_NumberOfSignificantClients" xlink:to="kcg_NumberOfSignificantClients_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_NumberOfSignificantClients_lbl" xml:lang="en-US"> Number of significant clients </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_NumberOfSignificantClients_lbl" xml:lang="en-US"> Number of Significant Clients </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_NumberOfSignificantClients_lbl" xml:lang="en-US"> Number of significant clients </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ComponentOfOtherOperatingCostAndExpenseTable" xlink:label="us-gaap_ComponentOfOtherOperatingCostAndExpenseTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComponentOfOtherOperatingCostAndExpenseTable" xlink:to="us-gaap_ComponentOfOtherOperatingCostAndExpenseTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComponentOfOtherOperatingCostAndExpenseTable_lbl" xml:lang="en-US"> Component of Other Operating Cost and Expense [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ComponentOfOtherOperatingCostAndExpenseGeneralAxis" xlink:label="us-gaap_ComponentOfOtherOperatingCostAndExpenseGeneralAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComponentOfOtherOperatingCostAndExpenseGeneralAxis" xlink:to="us-gaap_ComponentOfOtherOperatingCostAndExpenseGeneralAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComponentOfOtherOperatingCostAndExpenseGeneralAxis_lbl" xml:lang="en-US"> Component of Other Operating Cost and Expense, General [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ComponentOfOtherOperatingCostAndExpenseNameDomain" xlink:label="us-gaap_ComponentOfOtherOperatingCostAndExpenseNameDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComponentOfOtherOperatingCostAndExpenseNameDomain" xlink:to="us-gaap_ComponentOfOtherOperatingCostAndExpenseNameDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComponentOfOtherOperatingCostAndExpenseNameDomain_lbl" xml:lang="en-US"> Component of Other Operating Cost and Expense, Name [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeaseExpenseMember" xlink:label="us-gaap_OperatingLeaseExpenseMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseExpenseMember" xlink:to="us-gaap_OperatingLeaseExpenseMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseExpenseMember_lbl" xml:lang="en-US"> Operating Lease Expense [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LossContingencyRangeOfPossibleLossMinimum" xlink:label="us-gaap_LossContingencyRangeOfPossibleLossMinimum"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LossContingencyRangeOfPossibleLossMinimum" xlink:to="us-gaap_LossContingencyRangeOfPossibleLossMinimum_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LossContingencyRangeOfPossibleLossMinimum_lbl" xml:lang="en-US"> Loss Contingency, Range of Possible Loss, Minimum </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LossContingencyRangeOfPossibleLossMaximum" xlink:label="us-gaap_LossContingencyRangeOfPossibleLossMaximum"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LossContingencyRangeOfPossibleLossMaximum" xlink:to="us-gaap_LossContingencyRangeOfPossibleLossMaximum_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LossContingencyRangeOfPossibleLossMaximum_lbl" xml:lang="en-US"> Loss Contingency, Range of Possible Loss, Maximum </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditFacilityDescription" xlink:label="us-gaap_LineOfCreditFacilityDescription"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityDescription" xlink:to="us-gaap_LineOfCreditFacilityDescription_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityDescription_lbl" xml:lang="en-US"> Line of Credit Facility, Description </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCreditFacilityDescription_lbl" xml:lang="en-US"> Letter of credit </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SaleLeasebackTransactionTable" xlink:label="us-gaap_SaleLeasebackTransactionTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleLeasebackTransactionTable" xlink:to="us-gaap_SaleLeasebackTransactionTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SaleLeasebackTransactionTable_lbl" xml:lang="en-US"> Sale Leaseback Transaction [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_lbl" xml:lang="en-US"> Operating Leases, Future Minimum Payments Due, Current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_lbl" xml:lang="en-US"> Nine months ending December 31, 2011 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_lbl" xml:lang="en-US"> Operating Leases, Future Minimum Payments, Due in Two Years </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_lbl" xml:lang="en-US"> Year ending December 31, 2012 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_lbl" xml:lang="en-US"> Operating Leases, Future Minimum Payments, Due in Three Years </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_lbl" xml:lang="en-US"> Year ending December 31, 2013 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_lbl" xml:lang="en-US"> Operating Leases, Future Minimum Payments, Due in Four Years </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_lbl" xml:lang="en-US"> Year ending December 31, 2014 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_lbl" xml:lang="en-US"> Operating Leases, Future Minimum Payments, Due in Five Years </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_lbl" xml:lang="en-US"> Year ending December 31, 2015 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_lbl" xml:lang="en-US"> Operating Leases, Future Minimum Payments, Due Thereafter </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_lbl" xml:lang="en-US"> Thereafter through August 31, 2023 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" xml:lang="en-US"> Operating Leases, Future Minimum Payments Due </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" xml:lang="en-US"> Total </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TradingActivitiesGainLossByTypeTable" xlink:label="us-gaap_TradingActivitiesGainLossByTypeTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradingActivitiesGainLossByTypeTable" xlink:to="us-gaap_TradingActivitiesGainLossByTypeTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TradingActivitiesGainLossByTypeTable_lbl" xml:lang="en-US"> Trading Activities, Gain and Losses, by Type, by Income Statement Location [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TradingActivityByTypeAxis" xlink:label="us-gaap_TradingActivityByTypeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradingActivityByTypeAxis" xlink:to="us-gaap_TradingActivityByTypeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TradingActivityByTypeAxis_lbl" xml:lang="en-US"> Trading Activity, by Type [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TradingActivityByTypeDomain" xlink:label="us-gaap_TradingActivityByTypeDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradingActivityByTypeDomain" xlink:to="us-gaap_TradingActivityByTypeDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TradingActivityByTypeDomain_lbl" xml:lang="en-US"> Trading Activity, by Type [Domain] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_FuturesContractsMember" xlink:label="kcg_FuturesContractsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_FuturesContractsMember" xlink:to="kcg_FuturesContractsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_FuturesContractsMember_lbl" xml:lang="en-US"> Futures Contracts [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_FuturesContractsMember_lbl" xml:lang="en-US"> Futures Contracts [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_NotionalValueOfFuturesContract" xlink:label="kcg_NotionalValueOfFuturesContract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_NotionalValueOfFuturesContract" xlink:to="kcg_NotionalValueOfFuturesContract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_NotionalValueOfFuturesContract_lbl" xml:lang="en-US"> Notional Value Of Futures Contract </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_NotionalValueOfFuturesContract_lbl" xml:lang="en-US"> Notional Value Of Futures Contract </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_NotionalValueOfFuturesContract_lbl" xml:lang="en-US"> Notional Value </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_FairValueOfFuturesContract" xlink:label="kcg_FairValueOfFuturesContract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_FairValueOfFuturesContract" xlink:to="kcg_FairValueOfFuturesContract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_FairValueOfFuturesContract_lbl" xml:lang="en-US"> Fair Value Of Futures Contract </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_FairValueOfFuturesContract_lbl" xml:lang="en-US"> Fair Value Of Futures Contract </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="kcg_FairValueOfFuturesContract_lbl" xml:lang="en-US"> Fair Value reported in, Receivable from brokers, dealers and clearing organizations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_FairValueOfFuturesContract_lbl" xml:lang="en-US"> Fair Value reported in, Payable to brokers, dealers and clearing organizations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisGainLossIncludedInTradingRevenue" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisGainLossIncludedInTradingRevenue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisGainLossIncludedInTradingRevenue" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisGainLossIncludedInTradingRevenue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisGainLossIncludedInTradingRevenue_lbl" xml:lang="en-US"> Fair Value, Assets Measured on Recurring Basis, Gain (Loss) Included in Trading Revenue </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisGainLossIncludedInTradingRevenue_lbl" xml:lang="en-US"> Net trading revenue </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xml:lang="en-US"> Schedule of Segment Reporting Information, by Segment [Table] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_AssetsFromContinuingOperationsBeforeIncomeTaxes" xlink:label="kcg_AssetsFromContinuingOperationsBeforeIncomeTaxes"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_AssetsFromContinuingOperationsBeforeIncomeTaxes" xlink:to="kcg_AssetsFromContinuingOperationsBeforeIncomeTaxes_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_AssetsFromContinuingOperationsBeforeIncomeTaxes_lbl" xml:lang="en-US"> Assets from continuing operations before income taxes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_AssetsFromContinuingOperationsBeforeIncomeTaxes_lbl" xml:lang="en-US"> Assets From Continuing Operations Before Income Taxes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_AssetsFromContinuingOperationsBeforeIncomeTaxes_lbl" xml:lang="en-US"> Total assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationNoncurrent" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationNoncurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationNoncurrent" xlink:to="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_lbl" xml:lang="en-US"> Assets of Disposal Group, Including Discontinued Operation, Noncurrent </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_lbl" xml:lang="en-US"> Assets of Disposal Group, Including Discontinued Operation, Noncurrent, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_lbl" xml:lang="en-US"> Assets within discontinued operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="us-gaap_RestructuringCostAndReserveAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestructuringCostAndReserveAxis" xlink:to="us-gaap_RestructuringCostAndReserveAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestructuringCostAndReserveAxis_lbl" xml:lang="en-US"> Restructuring Cost and Reserve [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="us-gaap_TypeOfRestructuringDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfRestructuringDomain" xlink:to="us-gaap_TypeOfRestructuringDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TypeOfRestructuringDomain_lbl" xml:lang="en-US"> Type of Restructuring [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmployeeSeveranceMember" xlink:label="us-gaap_EmployeeSeveranceMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeSeveranceMember" xlink:to="us-gaap_EmployeeSeveranceMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeSeveranceMember_lbl" xml:lang="en-US"> Employee Severance [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_WriteDownLeaseAndContractTerminationMember" xlink:label="kcg_WriteDownLeaseAndContractTerminationMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_WriteDownLeaseAndContractTerminationMember" xlink:to="kcg_WriteDownLeaseAndContractTerminationMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_WriteDownLeaseAndContractTerminationMember_lbl" xml:lang="en-US"> Write Down Lease And Contract Termination [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_WriteDownLeaseAndContractTerminationMember_lbl" xml:lang="en-US"> Write Down Lease And Contract Termination [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_CapitalizedSoftwareAndIntangibleAssetWritedownMember" xlink:label="kcg_CapitalizedSoftwareAndIntangibleAssetWritedownMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_CapitalizedSoftwareAndIntangibleAssetWritedownMember" xlink:to="kcg_CapitalizedSoftwareAndIntangibleAssetWritedownMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_CapitalizedSoftwareAndIntangibleAssetWritedownMember_lbl" xml:lang="en-US"> Capitalized Software And Intangible Asset Writedown [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_CapitalizedSoftwareAndIntangibleAssetWritedownMember_lbl" xml:lang="en-US"> Capitalized Software And Intangible Asset Writedown [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ReductionOfWorkforcePercentage" xlink:label="kcg_ReductionOfWorkforcePercentage"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ReductionOfWorkforcePercentage" xlink:to="kcg_ReductionOfWorkforcePercentage_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ReductionOfWorkforcePercentage_lbl" xml:lang="en-US"> Reduction Of Workforce Percentage </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ReductionOfWorkforcePercentage_lbl" xml:lang="en-US"> Reduction Of Workforce Percentage </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_ReductionOfWorkforcePercentage_lbl" xml:lang="en-US"> Approximate percentage of workfoce reduction related to restructuring </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_CancellationOfReplacementHiresNumber" xlink:label="kcg_CancellationOfReplacementHiresNumber"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_CancellationOfReplacementHiresNumber" xlink:to="kcg_CancellationOfReplacementHiresNumber_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_CancellationOfReplacementHiresNumber_lbl" xml:lang="en-US"> Cancellation Of Replacement Hires Number </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_CancellationOfReplacementHiresNumber_lbl" xml:lang="en-US"> Cancellation Of Replacement Hires Number </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="kcg_CancellationOfReplacementHiresNumber_lbl" xml:lang="en-US"> Approximate number of replacement hires cancelled related to restructuring </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="us-gaap_RestructuringCharges"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestructuringCharges" xlink:to="us-gaap_RestructuringCharges_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestructuringCharges_lbl" xml:lang="en-US"> Restructuring </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_RestructuringCharges_lbl" xml:lang="en-US"> Restructuring Charges, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RestructuringCharges_lbl" xml:lang="en-US"> Expected costs incurred </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ComponentsOfRevenueAxis" xlink:label="kcg_ComponentsOfRevenueAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ComponentsOfRevenueAxis" xlink:to="kcg_ComponentsOfRevenueAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ComponentsOfRevenueAxis_lbl" xml:lang="en-US"> Components Of Revenue [Axis] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ComponentsOfRevenueAxis_lbl" xml:lang="en-US"> Components Of Revenue [Axis] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_ComponentsOfRevenueDomain" xlink:label="kcg_ComponentsOfRevenueDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_ComponentsOfRevenueDomain" xlink:to="kcg_ComponentsOfRevenueDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_ComponentsOfRevenueDomain_lbl" xml:lang="en-US"> Components Of Revenue [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_ComponentsOfRevenueDomain_lbl" xml:lang="en-US"> Components Of Revenue [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestIncomeMember" xlink:label="us-gaap_InterestIncomeMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestIncomeMember" xlink:to="us-gaap_InterestIncomeMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestIncomeMember_lbl" xml:lang="en-US"> Interest Income [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestExpenseMember" xlink:label="us-gaap_InterestExpenseMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpenseMember" xlink:to="us-gaap_InterestExpenseMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpenseMember_lbl" xml:lang="en-US"> Interest Expense [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EquityMember" xlink:label="us-gaap_EquityMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMember" xlink:to="us-gaap_EquityMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMember_lbl" xml:lang="en-US"> Equities [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ListedOptionsMember" xlink:label="us-gaap_ListedOptionsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ListedOptionsMember" xlink:to="us-gaap_ListedOptionsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ListedOptionsMember_lbl" xml:lang="en-US"> Listed Equity Options [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_USGovernmentAndGovernmentAgenciesAndAuthoritiesMember" xlink:label="us-gaap_USGovernmentAndGovernmentAgenciesAndAuthoritiesMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_USGovernmentAndGovernmentAgenciesAndAuthoritiesMember" xlink:to="us-gaap_USGovernmentAndGovernmentAgenciesAndAuthoritiesMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_USGovernmentAndGovernmentAgenciesAndAuthoritiesMember_lbl" xml:lang="en-US"> U.S. Government Obligations [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="us-gaap_CorporateDebtSecuritiesMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CorporateDebtSecuritiesMember" xlink:to="us-gaap_CorporateDebtSecuritiesMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CorporateDebtSecuritiesMember_lbl" xml:lang="en-US"> Corporate Debt [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmbeddedDerivativeFinancialInstrumentsMember" xlink:label="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember" xlink:to="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_lbl" xml:lang="en-US"> Embedded Conversion Derivative [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TotalReturnSwapMember" xlink:label="us-gaap_TotalReturnSwapMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TotalReturnSwapMember" xlink:to="us-gaap_TotalReturnSwapMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TotalReturnSwapMember_lbl" xml:lang="en-US"> Total Return Swap [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember" xlink:label="us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember" xlink:to="us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_lbl" xml:lang="en-US"> Mortgage-Backed Securities [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LoanInventoryMember" xlink:label="kcg_LoanInventoryMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LoanInventoryMember" xlink:to="kcg_LoanInventoryMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LoanInventoryMember_lbl" xml:lang="en-US"> Loan Inventory [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LoanInventoryMember_lbl" xml:lang="en-US"> Loan Inventory [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_SecuritizedLoanInventoryMember" xlink:label="kcg_SecuritizedLoanInventoryMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_SecuritizedLoanInventoryMember" xlink:to="kcg_SecuritizedLoanInventoryMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_SecuritizedLoanInventoryMember_lbl" xml:lang="en-US"> Securitized Loan Inventory [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_SecuritizedLoanInventoryMember_lbl" xml:lang="en-US"> Securitized Loan Inventory [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ForeignExchangeForwardMember" xlink:label="us-gaap_ForeignExchangeForwardMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignExchangeForwardMember" xlink:to="us-gaap_ForeignExchangeForwardMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignExchangeForwardMember_lbl" xml:lang="en-US"> Foreign Currency Forward Contracts [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_LiabilityToGnmaTrustsMember" xlink:label="kcg_LiabilityToGnmaTrustsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_LiabilityToGnmaTrustsMember" xlink:to="kcg_LiabilityToGnmaTrustsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_LiabilityToGnmaTrustsMember_lbl" xml:lang="en-US"> Liability To Gnma Trusts [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_LiabilityToGnmaTrustsMember_lbl" xml:lang="en-US"> Liability To Gnma Trusts [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_DeferredCompensationInvestmentsMember" xlink:label="kcg_DeferredCompensationInvestmentsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_DeferredCompensationInvestmentsMember" xlink:to="kcg_DeferredCompensationInvestmentsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_DeferredCompensationInvestmentsMember_lbl" xml:lang="en-US"> Deferred Compensation Investments [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_DeferredCompensationInvestmentsMember_lbl" xml:lang="en-US"> Deferred Compensation Investments [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_InvestmentInDeephavenFundsMember" xlink:label="kcg_InvestmentInDeephavenFundsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_InvestmentInDeephavenFundsMember" xlink:to="kcg_InvestmentInDeephavenFundsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_InvestmentInDeephavenFundsMember_lbl" xml:lang="en-US"> Investment in Deephaven Funds [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_InvestmentInDeephavenFundsMember_lbl" xml:lang="en-US"> Investment in Deephaven Funds [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:to="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_lbl" xml:lang="en-US"> Derivative Instruments, Gain (Loss) by Hedging Relationship [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="us-gaap_HedgingRelationshipDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_HedgingRelationshipDomain" xlink:to="us-gaap_HedgingRelationshipDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_HedgingRelationshipDomain_lbl" xml:lang="en-US"> Hedging Relationship [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="us-gaap_DesignatedAsHedgingInstrumentMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DesignatedAsHedgingInstrumentMember" xlink:to="us-gaap_DesignatedAsHedgingInstrumentMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DesignatedAsHedgingInstrumentMember_lbl" xml:lang="en-US"> Derivative Instruments Designated as Hedging Instruments [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="us-gaap_NondesignatedMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NondesignatedMember" xlink:to="us-gaap_NondesignatedMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NondesignatedMember_lbl" xml:lang="en-US"> Derivative Instruments Not Designated as Hedging Instruments [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeInstrumentRiskAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_lbl" xml:lang="en-US"> Derivative Instrument Risk [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_DerivativeContractTypeDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeContractTypeDomain_lbl" xml:lang="en-US"> Derivative Contract Type [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LoansPayableMember" xlink:label="us-gaap_LoansPayableMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayableMember" xlink:to="us-gaap_LoansPayableMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansPayableMember_lbl" xml:lang="en-US"> Term Credit Agreement [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="us-gaap_LineOfCreditMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditMember" xlink:to="us-gaap_LineOfCreditMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditMember_lbl" xml:lang="en-US"> Revolving Credit Agreement [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:label="us-gaap_SaleLeasebackTransactionDescriptionAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:to="us-gaap_SaleLeasebackTransactionDescriptionAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SaleLeasebackTransactionDescriptionAxis_lbl" xml:lang="en-US"> Sale Leaseback Transaction, Description [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SaleLeasebackTransactionNameDomain" xlink:label="us-gaap_SaleLeasebackTransactionNameDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleLeasebackTransactionNameDomain" xlink:to="us-gaap_SaleLeasebackTransactionNameDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SaleLeasebackTransactionNameDomain_lbl" xml:lang="en-US"> Sale Leaseback Transaction, Name [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CapitalLeaseObligationsMember" xlink:label="us-gaap_CapitalLeaseObligationsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalLeaseObligationsMember" xlink:to="us-gaap_CapitalLeaseObligationsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CapitalLeaseObligationsMember_lbl" xml:lang="en-US"> Gross Lease Obligations [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_SubleaseIncomeMember" xlink:label="kcg_SubleaseIncomeMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_SubleaseIncomeMember" xlink:to="kcg_SubleaseIncomeMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_SubleaseIncomeMember_lbl" xml:lang="en-US"> Sublease Income [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_SubleaseIncomeMember_lbl" xml:lang="en-US"> Sublease Income [Member] </label>
<loc xlink:type="locator" xlink:href="kcg-20110630.xsd#kcg_NetLeaseObligationsMember" xlink:label="kcg_NetLeaseObligationsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="kcg_NetLeaseObligationsMember" xlink:to="kcg_NetLeaseObligationsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="kcg_NetLeaseObligationsMember_lbl" xml:lang="en-US"> Net Lease Obligations [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="kcg_NetLeaseObligationsMember_lbl" xml:lang="en-US"> Net Lease Obligations [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ObligationsMember" xlink:label="us-gaap_ObligationsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ObligationsMember" xlink:to="us-gaap_ObligationsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ObligationsMember_lbl" xml:lang="en-US"> Other Obligations [Member] </label>
</labelLink>
</linkbase>

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