ATRA - CIK 0001604464
Atara Biotherapeutics, Inc. has filed 999 documents with the SEC between 2015 and 2026. The most frequent type is insider trade (542 filings), alongside the regular cadence of annual reports, quarterly reports, and event disclosures every public company must make. Use the filters to focus on one filing type, or flip the sort to trace the company's history from its earliest paperwork.
Data parsed from SEC EDGAR XBRL filings. See the full market cap rankings.
| Filing | Type | Filed | Period covered |
|---|---|---|---|
| Insider trade | 4 | 2026-05-20 | 2026-05-18 |
| Insider trade | 4 | 2026-05-20 | 2026-05-18 |
| Insider sale notice | 144 | 2026-05-18 | - |
| Insider sale notice | 144 | 2026-05-18 | - |
| SCHEDULE 13D/A | - | 2026-05-14 | - |
| SCHEDULE 13G | - | 2026-05-13 | - |
| Prospectus supplement | 424B5 | 2026-05-12 | - |
| Quarterly report | 10-Q | 2026-05-12 | 2026-03-31 |
| Major company event | 8-K | 2026-05-12 | 2026-05-12 |
| SCHEDULE 13D/A | - | 2026-05-11 | - |
| Insider trade | 4 | 2026-05-11 | 2026-05-07 |
| Insider trade | 4 | 2026-05-11 | 2026-05-07 |
| New insider ownership | 3 | 2026-05-11 | 2026-05-07 |
| SCHEDULE 13G | - | 2026-05-08 | - |
| Insider sale notice | 144 | 2026-05-07 | - |
| Major company event | 8-K | 2026-05-07 | 2026-05-07 |
| SCHEDULE 13G/A | - | 2026-05-07 | - |
| Major company event | 8-K | 2026-05-01 | 2026-04-30 |
| Proxy statement | DEF 14A | 2026-04-24 | 2026-04-24 |
| Proxy materials | DEFA14A | 2026-04-24 | - |
| EFFECT | - | 2026-03-25 | - |
| 424B3 | - | 2026-03-25 | - |
| Company correspondence | CORRESP | 2026-03-23 | - |
| SEC correspondence | UPLOAD | 2026-03-20 | - |
| Insider trade | 4 | 2026-03-19 | 2026-03-17 |
| Securities registration | S-3 | 2026-03-17 | - |
| Prospectus supplement | 424B5 | 2026-03-16 | - |
| Annual report | 10-K | 2026-03-16 | 2025-12-31 |
| Major company event | 8-K | 2026-03-16 | 2026-03-16 |
| Major company event | 8-K | 2026-03-12 | 2026-03-12 |
| Insider trade | 4 | 2026-03-11 | 2026-03-09 |
| Insider trade | 4 | 2026-03-11 | 2026-03-09 |
| Insider trade | 4 | 2026-03-04 | 2026-03-02 |
| Insider trade | 4 | 2026-03-04 | 2026-03-02 |
| Major company event | 8-K | 2026-03-03 | 2026-03-03 |
| Insider sale notice | 144 | 2026-03-02 | - |
| Insider sale notice | 144 | 2026-03-02 | - |
| Major company event | 8-K | 2026-02-23 | 2026-02-20 |
| SCHEDULE 13D/A | - | 2026-01-14 | - |
| Insider trade | 4 | 2026-01-14 | 2026-01-12 |
| Insider sale notice | 144 | 2026-01-12 | - |
| Major company event | 8-K | 2026-01-12 | 2026-01-12 |
| Major company event | 8-K | 2026-01-02 | 2025-12-30 |
| Insider trade | 4 | 2025-12-01 | 2025-11-28 |
| Insider trade | 4 | 2025-11-19 | 2025-11-17 |
| Insider trade | 4 | 2025-11-19 | 2025-11-17 |
| Insider sale notice | 144 | 2025-11-17 | - |
| Insider sale notice | 144 | 2025-11-17 | - |
| SCHEDULE 13D/A | - | 2025-11-14 | - |
| SCHEDULE 13G/A | - | 2025-11-14 | - |