| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Nguyen AnhCo | President and CEO, Director | C/O ATARA BIOTHERAPEUTICS, INC., 1280 RANCHO CONEJO BOULEVARD, THOUSAND OAKS | /s/ John Chao, Attorney-in-Fact for AnhCo Nguyen | 19 Nov 2025 | 0001977970 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | ATRA | Common Stock | Sale | $37,699 | -2,859 | -4.2% | $13.19 | 65,030 | 17 Nov 2025 | Direct | F1, F2 |
| transaction | ATRA | Common Stock | Sale | $739 | -56 | -0.09% | $13.19 | 64,974 | 17 Nov 2025 | Direct | F1, F2 |
| Id | Content |
|---|---|
| F1 | Shares sold automatically to satisfy tax withholding obligations in connection with the vesting of previously granted restricted stock units, pursuant to a sale-to-cover provision in the award agreement. |
| F2 | The sale price of the reporting person's shares represents the weighted average price of all shares sold by a broker on November 17, 2025 on behalf of a group of employees of the Issuer to satisfy the payment of withholding tax liability of such employees. |