X0306 4 2022-08-16 0001604464 Atara Biotherapeutics, Inc. ATRA 0001809916 Murugan Amar C/O ATARA BIOTHERAPEUTICS, INC. 611 GATEWAY BOULEVARD, SUITE 900 SOUTH SAN FRANCISCO CA 94080 true SVP, GC & Secretary Common Stock 2022-08-16 4 S 0 1196 5.034 D 133432 D Common Stock 2022-08-16 4 S 0 2234 5.035 D 131198 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 August 16, 2022 on behalf of a group of employees of the Issuer to satisfy the payment of withholding tax liability of such employee. Includes 893 shares purchased under the Issuer's Employee Stock Purchase Plan on May 31, 2022. /s/ David Tucker, Attorney-in-Fact for Amar Murugan 2022-08-18