X0508 4 2023-11-13 0001604464 Atara Biotherapeutics, Inc. ATRA 0001329959 Gallagher Carol Giltner C/O ATARA BIOTHERAPEUTICS, INC. 2380 CONEJO SPECTRUM ST, SUITE 200 THOUSAND OAKS CA 91320 true false Common Stock 2023-11-13 4 P 0 179020 0.2236 A 368438 D Common Stock 2023-11-14 4 P 0 90980 0.3098 A 459418 D Represents the weighted average purchase price. The shares were purchased in multiple transactions at prices ranging from $0.205 to $0.251. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this Form 4. Represents the weighted average purchase price. The shares were purchased in multiple transactions at prices ranging from $0.2862 to $0.3229. /s/ Jeff Kiekhofer, Attorney-in-Fact 2023-11-15