16 insiders reported 58 Form 4 transactions for Atara Biotherapeutics, Inc. (ATRA) over the past 18 months (most recent 2026-06-11). Recent activity: HEIDEN WILLIAM K (Director) Buy 12,000 shares, Fust Matthew K (Director) Buy 12,000 shares, Ciongoli Gregory Austin (Director) Buy 12,000 shares, Nguyen AnhCo (President and CEO) Sell 5,241 shares, Grant-Huerta Yanina (Chief Accounting Officer) Sell 2,414 shares. Source: SEC Form 4.
| Date | Insider | Title | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-06-11 | HEIDEN WILLIAM K | Director | Buy | 12,000 | $0 |
| 2026-06-11 | Fust Matthew K | Director | Buy | 12,000 | $0 |
| 2026-06-11 | Ciongoli Gregory Austin | Director | Buy | 12,000 | $0 |
| 2026-05-20 | Nguyen AnhCo | President and CEO | Sell | 5,241 | $47,845 |
| 2026-05-20 | Grant-Huerta Yanina | Chief Accounting Officer | Sell | 2,414 | $22,036 |
| 2026-05-11 | Huang James | Director | Sell | 313,446 | $3.2M |
| 2026-05-11 | EcoR1 Capital, LLC | Insider | Buy | 507,407 | $4.7M |
| 2026-05-11 | Panacea Innovation Ltd | Insider | Sell | 313,446 | $3.2M |
| 2026-03-19 | Huang James | Director | Buy | 259,163 | $0 |
| 2026-03-19 | Panacea Innovation Ltd | Insider | Buy | 259,163 | $0 |
| 2026-03-19 | Huang James | Director | Sell | 5 | $26 |
| 2026-03-19 | Panacea Innovation Ltd | Insider | Sell | 5 | $26 |
| 2026-03-11 | Grant-Huerta Yanina | Chief Accounting Officer | Buy | 20,300 | $0 |
| 2026-03-11 | Nguyen AnhCo | President and CEO | Buy | 81,100 | $0 |
| 2026-03-04 | Grant-Huerta Yanina | Chief Accounting Officer | Sell | 24 | $122 |
| 2026-03-04 | Grant-Huerta Yanina | Chief Accounting Officer | Sell | 1,603 | $8,143 |
| 2026-03-04 | Grant-Huerta Yanina | Chief Accounting Officer | Sell | 377 | $1,915 |
| 2026-03-04 | Grant-Huerta Yanina | Chief Accounting Officer | Sell | 100 | $508 |
| 2026-03-04 | Nguyen AnhCo | President and CEO | Sell | 198 | $1,006 |
| 2026-03-04 | Nguyen AnhCo | President and CEO | Sell | 58 | $295 |
| 2026-03-04 | Nguyen AnhCo | President and CEO | Sell | 1,298 | $6,607 |
| 2026-03-04 | Nguyen AnhCo | President and CEO | Sell | 1,442 | $7,340 |
| 2026-01-14 | Huang James | Director | Sell | 80,554 | $488,963 |
| 2026-01-14 | Panacea Innovation Ltd | Insider | Sell | 80,554 | $488,963 |
| 2025-12-01 | Huang James | Director | Buy | 48,737 | $0 |
Source: SEC Form 4 filings · as of 2026-06-11