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Ownership Document
|
| Schema Version: X0508 |
| Document Type: 4 |
| Period of Report: 4/1/24 |
| Not Subject to Section 16? No |
| Issuer: |
| Issuer CIK: 1860782 |
| Issuer Name: 2seventy bio, Inc. |
| Issuer Trading Symbol: TSVT |
| Reporting Owner: |
| Reporting Owner ID: |
| | Owner CIK: 1547658 |
| | Owner Name: Baird William D III |
| Reporting Owner Address: |
| | Owner Street 1: 60 BINNEY STREET |
| | Owner Street 2: |
| | Owner City: CAMBRIDGE |
| | Owner State: MA |
| | Owner ZIP Code: 02142 |
| | Owner State Description: |
| Reporting Owner Relationship: |
| | Is Director? Yes |
| | Is Officer? Yes |
| | Is Ten Percent Owner? No |
| | Is Other? No |
| | Officer Title: President and CEO |
| | Other Text: |
| Aff 10b5 One? No |
| Non-Derivative Table: |
| Non-Derivative Transaction: |
| | Security Title: |
| | | Value: Common Stock |
| | | Footnote ID: F1 |
| | Transaction Date: |
| | | Value: 4/1/24 |
| | Deemed Execution Date: |
| | Transaction Coding: |
| | | Transaction Form Type: 4 |
| | | Transaction Code: A |
| | | Equity Swap Involved? No |
| | Transaction Timeliness: |
| | Transaction Amounts: |
| | | Transaction Shares: |
| Value: 56,250.00 |
| | | Transaction Price Per Share: |
| Value: 0.00 |
| | | Transaction Acquired-Disposed Code: |
| Value: A |
| | Post-Transaction Amounts: |
| | | Shares Owned Following Transaction: |
| Value: 308,585.00 |
| | Ownership Nature: |
| | | Direct or Indirect Ownership: |
| Value: D |
| Derivative Table: |
| Derivative Transaction: |
| | Security Title: |
| | | Value: Stock Options (Right to buy) |
| | Conversion or Exercise Price: |
| | | Value: 5.79 |
| | Transaction Date: |
| | | Value: 4/1/24 |
| | Deemed Execution Date: |
| | Transaction Coding: |
| | | Transaction Form Type: 4 |
| | | Transaction Code: A |
| | | Equity Swap Involved? No |
| | Transaction Timeliness: |
| | Transaction Amounts: |
| | | Transaction Shares: |
| Value: 112,500.00 |
| | | Transaction Price Per Share: |
| Value: 0.00 |
| | | Transaction Acquired-Disposed Code: |
| Value: A |
| | Exercise Date: |
| | | Footnote ID: F2 |
| | Expiration Date: |
| | | Value: 4/1/34 |
| | Underlying Security: |
| | | Underlying Security Title: |
| Value: Common Stock |
| | | Underlying Security Shares: |
| Value: 112,500.00 |
| | Post-Transaction Amounts: |
| | | Shares Owned Following Transaction: |
| Value: 112,500.00 |
| | Ownership Nature: |
| | | Direct or Indirect Ownership: |
| Value: D |
| Footnotes: |
| Footnote - F1: This restricted stock unit award vests ratably over a four-year period in annual installments with the first installment vesting on March 15, 2025, subject to the Reporting Person's continued service through the applicable vesting date. |
| Footnote - F2: This stock option vests over a four-year period at the rate of 25% on March 15, 2025, and then in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date. |
| Remarks: |
| Owner Signature: |
| Signature Name: /s/ Iya Kessler, Attorney-in-Fact |
| Signature Date: 4/3/24 |
