ATRA (Atara Biotherapeutics, Inc)
Insider Trading Activity
Every open-market purchase and sale reported by ATRA officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-09-04 | Brian N Cherry | Director | Buy | — | — |
| 2026-08-26 | AnhCo Nguyen | President and CEO | Sell | — | — |
| 2026-07-24 | Redmile Group, LLC | Director | MIXED | — | — |
| 2026-06-15 | Brian N Cherry | Director | A | — | — |
| 2026-06-11 | WILLIAM K HEIDEN | Director | A | — | — |
| 2026-06-11 | Gregory Austin Ciongoli | Director | A | — | — |
| 2026-06-11 | Matthew K Fust | Director | A | — | — |
| 2026-05-20 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | — | — |
| 2026-05-20 | AnhCo Nguyen | President and CEO | Sell | — | — |
| 2026-05-11 | James Huang | Director | Sell | — | — |
| 2026-05-11 | EcoR1 Capital, LLC | 10%+ Owner | Buy | — | — |
| 2026-03-19 | Panacea Innovation Ltd | 10%+ Owner | MIXED | — | — |
| 2026-03-11 | Yanina Grant-Huerta | Chief Accounting Officer | A | — | — |
| 2026-03-11 | AnhCo Nguyen | President and CEO | A | — | — |
| 2026-03-04 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | — | — |
| 2026-03-04 | AnhCo Nguyen | President and CEO | Sell | — | — |
| 2026-01-14 | Panacea Innovation Ltd | 10%+ Owner | Sell | — | — |
| 2025-12-01 | James Huang | Director | MIXED | — | — |
| 2025-11-19 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | — | — |
| 2025-11-19 | AnhCo Nguyen | President and CEO | Sell | — | — |
| 2025-08-20 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | — | — |
| 2025-08-20 | AnhCo Nguyen | President and CEO | Sell | — | — |
| 2025-08-19 | James Huang | Director | Buy | — | — |
| 2025-07-21 | Panacea Innovation Ltd | 10%+ Owner | Buy | — | — |
| 2025-06-12 | WILLIAM K HEIDEN | Director | A | — | — |
| 2025-06-12 | AMEET MALLIK | Director | A | — | — |
| 2025-06-12 | Carol Giltner Gallagher | Director | A | — | — |
| 2025-06-12 | Pascal Touchon | Director | A | — | — |
| 2025-06-12 | Maria Grazia Roncarolo | Director | A | — | — |
| 2025-06-12 | Matthew K Fust | Director | A | — | — |
| 2025-05-20 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | — | — |
| 2025-05-20 | AnhCo Nguyen | President and CEO | Sell | — | — |
| 2025-05-16 | Adiumentum Capital Fund I LP | Director | A | — | — |
| 2025-04-02 | Eric J Hyllengren | — | D | — | — |
| 2025-03-05 | Eric J Hyllengren | EVP, CFO and COO | Sell | — | — |
| 2025-03-05 | AnhCo Nguyen | President and CEO | Sell | — | — |
| 2025-03-05 | Jill Henrich | EVP, Chief Regulatory Officer | Sell | — | — |
| 2025-01-29 | Eric J Hyllengren | EVP, CFO and COO | A | — | — |
| 2024-11-20 | Jill Henrich | EVP, Chief Regulatory Officer | Sell | — | — |
| 2024-11-20 | AnhCo Nguyen | President and CEO | Sell | — | — |
| 2024-11-20 | Eric J Hyllengren | EVP, CFO and COO | Sell | — | — |
| 2024-09-11 | AnhCo Nguyen | President and CEO | A | — | — |
| 2024-08-20 | Amar Murugan | EVP, Chief Legal Officer | Sell | — | — |
| 2024-08-20 | Jill Henrich | EVP, Global Head RA & Quality | Sell | — | — |
| 2024-08-20 | Eric J Hyllengren | EVP, CFO | Sell | — | — |
| 2024-08-20 | Pascal Touchon | President and CEO | Sell | — | — |
| 2024-08-20 | AnhCo Nguyen | EVP, Chief Sci. & Tech Officer | Sell | — | — |
| 2024-08-14 | Pascal Touchon | President and CEO | D | — | — |
| 2024-05-20 | Eric J Hyllengren | EVP, CFO | Sell | — | — |
| 2024-05-20 | Jill Henrich | EVP, Global Head RA & Quality | Sell | — | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| — | 10%+ Owner | 1,552,000 | — |
| — | Director | 1,221,395 | — |
| — | Director | 1,209,395 | — |
| — | Director | 636,852 | — |
| — | 10%+ Owner | 307,899 | — |
| — | Director | 307,894 | — |
| — | Director | 166,486 | — |
| — | President and CEO | 132,775 | — |
| — | President and CEO | 77,955 | — |
| — | 10%+ Owner | 76,112 | — |
| — | 10%+ Owner | 75,735 | — |
| — | EVP, CFO and COO | 56,231 | — |
| — | Chief Accounting Officer | 49,636 | — |
| — | Director | 35,518 | — |
| — | Director | 34,188 | — |
| — | Director | 30,188 | — |
| — | EVP, Chief Legal Officer | 27,108 | — |
| — | Chief Executive Officer | 24,977 | — |
| — | Director | 22,533 | — |
| — | EVP, Chief Regulatory Officer | 18,679 | — |
| — | Director | 17,368 | — |
| — | Director | 16,928 | — |
| — | EVP, Head of R&D | 11,632 | — |
| — | EVP, Chief Technical Officer | 11,040 | — |
| — | EVP, R&D & Chief Scientific Of | 10,986 | — |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the ATRA quote page; the site-wide leaderboard is on the insider transactions hub.