X0609 4 2026-09-04 0001604464 Atara Biotherapeutics, Inc. ATRA 0001290922 Cherry Brian N false C/O ATARA BIOTHERAPEUTICS, INC. 1280 RANCHO CONEJO BOULEVARD THOUSAND OAKS CA 91320 true false false false false Common Stock 2026-09-04 4 P false 104166 9.60 A 166486 D Represents shares purchased by the Reporting Person from the Issuer, through its sales agent, pursuant to that certain Sales Agreement, dated November 1, 2023, by and between the Issuer and TD Securities (USA) LLC. Exhibit List: Exhibit 24 - Power of Attorney /s/ Brian Cherry 2026-09-04