X0306 4 2022-11-16 0001604464 Atara Biotherapeutics, Inc. ATRA 0001553335 Dupont Jakob C/O ATARA BIOTHERAPEUTICS, INC. 2380 CONEJO SPECTRUM ST, SUITE 200 THOUSAND OAKS CA 91320 true EVP, Head of R&D Common Stock 2022-11-16 4 S 0 3218 4.49 D 155664 D Common Stock 2022-11-16 4 S 0 1124 4.491 D 154540 D Shares sold pursuant to a 10b5-1 arrangement to satisfy tax obligations in connection with the vesting of previously granted restricted stock units. The sale price of the reporting person's shares represents the weighted average price of all shares sold by a broker on November 16, 2022 and November 17, 2022 on behalf of a group of employees of the Issuer to satisfy the payment of withholding tax liability of such employee. Exhibit List: Exhibit 24 - Power of Attorney /s/ Jeff Kiekhofer, Attorney-in-Fact for Jakob Dupont 2022-11-18