Legal Insider Trading Data | Free and Professional Subscription Services | Insider Insights urn:uuid:e9d992c1-0414-315f-b989-7f7daabcb82c 2026-10-28T07:54:37-04:00 Jonathan Moreland Profit from legal insider trading. InsiderInsights.com provides free insider trading data tools and resources, and professional grade subscription based real time Form 4 data, analysis and services ATRA: CHERRY BRIAN N (DIR) Bought (B) 104,166 Shares of ATARA BIOTHERAPEUTICS INC for $9.60 on 9/4 urn:uuid:2187cf9b-3965-0f43-6b49-c6fd51d387ab 2026-09-04T18:20:04-04:00 ATRA: NGUYEN ANHCO (PR,CEO,DIR) Sold (S) 5,062 Shares of ATARA BIOTHERAPEUTICS INC for $8.08 on 8/17 urn:uuid:743b3d32-2203-d018-fd08-2e28def8bd57 2026-08-26T19:45:25-04:00 ATRA: REDMILE GROUP LLC (DIR) Disposed (JS) 60 Shares of ATARA BIOTHERAPEUTICS INC for $0.00 on 7/22 urn:uuid:28307354-4262-5613-01fa-4185de1905d7 2026-07-24T21:00:10-04:00 ATRA: REDMILE GROUP LLC (DIR) Acquired (JB) 195,211 Shares of ATARA BIOTHERAPEUTICS INC for $0.00 on 7/22 urn:uuid:bbdf56e5-232d-645a-b56b-8a7d3fcb3c84 2026-07-24T21:00:10-04:00 ATRA: SARNEY KEVIN G (CFO) Filed a Form 3, Becoming a Registered Insider at ATARA BIOTHERAPEUTICS INC With Initial Holdings of 0 urn:uuid:f8dbddfc-54d0-c4c4-9523-5bdd1bb5971f 2026-07-06T16:14:19-04:00 ATRA: CHERRY BRIAN N (DIR) Acquired (JB) 24k Shares of ATARA BIOTHERAPEUTICS INC for $0.00 on 6/11 urn:uuid:182a4a92-2372-e74f-3667-a920bee39ef1 2026-06-15T18:51:31-04:00 ATRA: CHERRY BRIAN N (DIR) Filed a Form 3, Becoming a Registered Insider at ATARA BIOTHERAPEUTICS INC With Initial Direct Holdings of 38,320 urn:uuid:eb6e3b19-7c9f-c8df-bb69-d99d346fc59b 2026-06-15T18:48:52-04:00 ATRA: HEIDEN WILLIAM K (DIR) Acquired (JB) 12k Shares of ATARA BIOTHERAPEUTICS INC for $0.00 on 6/9 urn:uuid:28159955-97b4-50e3-52c5-41e90dc4b756 2026-06-11T16:37:50-04:00 ATRA: FUST MATTHEW K (DIR) Acquired (JB) 12k Shares of ATARA BIOTHERAPEUTICS INC for $0.00 on 6/9 urn:uuid:5d29ed84-260d-f3f3-3b63-7f12f13be562 2026-06-11T16:36:58-04:00 ATRA: CIONGOLI GREGORY AUSTIN (DIR,BO) Acquired (JB) 12k Shares of ATARA BIOTHERAPEUTICS INC for $0.00 on 6/9 urn:uuid:509a5223-dcde-f74f-58ee-762fc690054c 2026-06-11T16:36:04-04:00