ATRA · Insider Trading
Atara Biotherapeutics, Inc
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.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-09-04 | Brian N Cherry | Director | Buy | +104,166 | +$999.99K |
| 2026-08-26 | AnhCo Nguyen | President and CEO | Sell | −5,062 | −$40.88K |
| 2026-07-24 | Redmile Group, LLC | Director | MIXED | +390,302 | — |
| 2026-06-15 | Brian N Cherry | Director | A | +24,000 | — |
| 2026-06-11 | William K Heiden | Director | A | +12,000 | — |
| 2026-06-11 | Gregory Austin Ciongoli | Director | A | +12,000 | — |
| 2026-06-11 | Matthew K Fust | Director | A | +12,000 | — |
| 2026-05-20 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | −2,414 | −$22.04K |
| 2026-05-20 | AnhCo Nguyen | President and CEO | Sell | −5,241 | −$47.84K |
| 2026-05-11 | James Huang | Director | Sell | −626,892 | −$6.33M |
| 2026-05-11 | EcoR1 Capital, LLC | 10%+ Owner | Buy | +507,407 | +$4.74M |
| 2026-03-19 | Panacea Innovation Ltd | 10%+ Owner | MIXED | +518,316 | −$0 |
| 2026-03-11 | Yanina Grant-Huerta | Chief Accounting Officer | A | +20,300 | — |
| 2026-03-11 | AnhCo Nguyen | President and CEO | A | +81,100 | — |
| 2026-03-04 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | −2,104 | −$10.69K |
| 2026-03-04 | AnhCo Nguyen | President and CEO | Sell | −2,996 | −$15.24K |
| 2026-01-14 | Panacea Innovation Ltd | 10%+ Owner | Sell | −161,108 | −$978.04K |
| 2025-12-01 | James Huang | Director | MIXED | +97,472 | −$18 |
| 2025-11-19 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | −1,804 | −$23.79K |
| 2025-11-19 | AnhCo Nguyen | President and CEO | Sell | −2,915 | −$38.44K |
| 2025-08-20 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | −1,809 | −$21.01K |
| 2025-08-20 | AnhCo Nguyen | President and CEO | Sell | −2,958 | −$34.36K |
| 2025-08-19 | James Huang | Director | Buy | +110,000 | +$1.34M |
| 2025-07-21 | Panacea Innovation Ltd | 10%+ Owner | Buy | +38,670 | +$372.74K |
| 2025-06-12 | William K Heiden | Director | A | +7,828 | — |
| 2025-06-12 | Ameet Mallik | Director | A | +7,828 | — |
| 2025-06-12 | Carol Giltner Gallagher | Director | A | +7,828 | — |
| 2025-06-12 | Pascal Touchon | Director | A | +7,828 | — |
| 2025-06-12 | Maria Grazia Roncarolo | Director | A | +7,828 | — |
| 2025-06-12 | Matthew K Fust | Director | A | +7,828 | — |
| 2025-05-20 | Yanina Grant-Huerta | Chief Accounting Officer | Sell | −2,218 | −$15.00K |
| 2025-05-20 | AnhCo Nguyen | President and CEO | Sell | −3,276 | −$22.16K |
| 2025-05-16 | Adiumentum Capital Fund I LP | Director | A | +226,716 | +$1.50M |
| 2025-04-02 | Eric J Hyllengren | — | D | −13,838 deriv. | — |
| 2025-03-05 | Eric J Hyllengren | EVP, CFO and COO | Sell | −1,211 | −$8.47K |
| 2025-03-05 | AnhCo Nguyen | President and CEO | Sell | −3,331 | −$23.31K |
| 2025-03-05 | Jill Henrich | EVP, Chief Regulatory Officer | Sell | −1,059 | −$7.41K |
| 2025-01-29 | Eric J Hyllengren | EVP, CFO and COO | A | +34,050 | — |
| 2024-11-20 | Jill Henrich | EVP, Chief Regulatory Officer | Sell | −1,000 | −$11.20K |
| 2024-11-20 | AnhCo Nguyen | President and CEO | Sell | −1,664 | −$18.63K |
| 2024-11-20 | Eric J Hyllengren | EVP, CFO and COO | Sell | −1,364 | −$15.27K |
| 2024-09-11 | AnhCo Nguyen | President and CEO | A | +45,000 | — |
| 2024-08-20 | Amar Murugan | EVP, Chief Legal Officer | Sell | −1,158 | −$7.68K |
| 2024-08-20 | Jill Henrich | EVP, Global Head RA & Quality | Sell | −963 | −$6.38K |
| 2024-08-20 | Eric J Hyllengren | EVP, CFO | Sell | −1,070 | −$7.09K |
| 2024-08-20 | Pascal Touchon | President and CEO | Sell | −3,038 | −$20.14K |
| 2024-08-20 | AnhCo Nguyen | EVP, Chief Sci. & Tech Officer | Sell | −1,821 | −$12.07K |
| 2024-08-14 | Pascal Touchon | President and CEO | D | −25,755 deriv. | — |
| 2024-05-20 | Eric J Hyllengren | EVP, CFO | Sell | −28,648 | −$17.68K |
| 2024-05-20 | Jill Henrich | EVP, Global Head RA & Quality | Sell | −25,750 | −$15.89K |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| EcoR1 Capital, LLC | 10%+ Owner | 1,552,000 | $12.96M |
| Gregory Austin Ciongoli | Director | 1,221,395 | $10.20M |
| Adiumentum Capital Fund I LP | Director | 1,209,395 | $10.10M |
| Redmile Group, LLC | Director | 636,852 | $5.32M |
| Panacea Innovation Ltd | 10%+ Owner | 307,899 | $2.57M |
| James Huang | Director | 307,894 | $2.57M |
| Brian N Cherry | Director | 166,486 | $1.39M |
| AnhCo Nguyen | President and CEO | 132,775 | $1.11M |
| Pascal Touchon | President and CEO | 77,955 | $650.92K |
| Eric J Hyllengren | EVP, CFO and COO | 56,231 | $469.53K |
| Yanina Grant-Huerta | Chief Accounting Officer | 49,636 | $414.46K |
| Carol Giltner Gallagher | Director | 35,518 | $296.58K |
| William K Heiden | Director | 34,188 | $285.47K |
| Matthew K Fust | Director | 30,188 | $252.07K |
| Jill Henrich | EVP, Chief Regulatory Officer | 18,679 | $155.97K |
| Maria Grazia Roncarolo | Director | 17,368 | $145.02K |
| Ameet Mallik | Director | 16,928 | $141.35K |
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.
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.