| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Grant-Huerta Yanina | Chief Accounting Officer | C/O ATARA BIOTHERAPEUTICS, INC., 1280 RANCHO CONEJO BOULEVARD, THOUSAND OAKS | /s/ John Chao, Attorney-in-Fact for Yanina Grant-Huerta | 04 Mar 2026 | 0002064348 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | ATRA | Common Stock | Sale | $122 | -24 | -0.07% | $5.08 | 33,830 | 02 Mar 2026 | Direct | F1, F2, F3 |
| transaction | ATRA | Common Stock | Sale | $8,145 | -1,603 | -4.7% | $5.08 | 32,227 | 02 Mar 2026 | Direct | F1, F2 |
| transaction | ATRA | Common Stock | Sale | $1,916 | -377 | -1.2% | $5.08 | 31,850 | 02 Mar 2026 | Direct | F1, F2 |
| transaction | ATRA | Common Stock | Sale | $508 | -100 | -0.31% | $5.08 | 31,750 | 02 Mar 2026 | 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 March 2, 2026 on behalf of a group of employees of the Issuer to satisfy the payment of withholding tax liability of such employees. |
| F3 | This amount includes 400 shares purchased under the Issuer's Employee Stock Purchase Plan on November 28, 2025. |