| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Sinha Vikas | Chief Financial Officer | 301 BINNEY STREET, CAMBRIDGE | /s/ Junlin Ho, Attorney-in-Fact for Vikas Sinha | 15 Jan 2026 | 0001337845 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | SRRK | Common Stock | Sale | $715,438 | -16,755 | -2.8% | $42.70 | 583,245 | 13 Jan 2026 | Direct | F1, F2, F3 |
| Id | Content |
|---|---|
| F1 | Represents the number of shares required to be sold by the Reporting Person to cover the tax withholding obligation in connection with the vesting of restricted stock units subject to performance-and time-based vesting conditions ("PSUs"). The sale is mandated by the Issuer's election under its equity incentive plans to require the Reporting Person to fund this tax withholding obligation by completing a "sell to cover" transaction with a brokerage firm designated by the Issuer. This sale does not represent a discretionary trade by the Reporting Person. Each PSU represents the contingent right to receive upon vesting of the PSU, one share of the Issuer's common stock. |
| F2 | (continued) The shares vested pursuant to awards that were granted on April 27, 2025. 50,000 shares subject to this PSU vested on January 12, 2026, with an additional 50,000 shares scheduled to vest on April 27, 2027 and the remaining shares vesting in tranches of a combination of performance-based vesting tied to the Issuer's common stock achieving certain price targets and time-based vesting over four year, provided the Reporting Person continues to have a service relationship with the Issuer on each such vesting date. Any PSUs that have not vested on or prior to April 27, 2029 will be forfeited for no consideration. |
| F3 | 33,245 shares of common stock, 100,000 restricted stock units and 450,000 PSUs. |