17 insiders reported 61 Form 4 transactions for Atara Biotherapeutics, Inc. (ATRA) over the past 18 months (most recent 2026-09-04). Recent activity: Cherry Brian N (Director) Buy 104,166 shares, Nguyen AnhCo (President and CEO) Sell 5,062 shares, Redmile Group, LLC (Director) Buy 195,211 shares, Green Jeremy (Director) Buy 195,211 shares, Redmile Group, LLC (Director) Sell 60 shares. Source: SEC Form 4.
| Date | Insider | Title | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-09-04 | Cherry Brian N | Director | Buy | 104,166 | $999,994 |
| 2026-08-26 | Nguyen AnhCo | President and CEO | Sell | 5,062 | $40,883 |
| 2026-07-24 | Redmile Group, LLC | Director | Buy | 195,211 | $0 |
| 2026-07-24 | Green Jeremy | Director | Buy | 195,211 | $0 |
| 2026-07-24 | Redmile Group, LLC | Director | Sell | 60 | $0 |
| 2026-07-24 | Green Jeremy | Director | Sell | 60 | $0 |
| 2026-06-15 | Cherry Brian N | Director | Buy | 24,000 | $0 |
| 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 | $47,850 |
| 2026-05-20 | Grant-Huerta Yanina | Chief Accounting Officer | Sell | 2,414 | $22,040 |
| 2026-05-11 | Huang James | Director | Sell | 313,446 | $3.2M |
| 2026-05-11 | Panacea Innovation Ltd | 10% Owner | Sell | 313,446 | $3.2M |
| 2026-05-11 | EcoR1 Capital, LLC | 10% Owner | Buy | 507,407 | $4.7M |
| 2026-03-19 | Huang James | Director | Buy | 259,163 | $0 |
| 2026-03-19 | Panacea Innovation Ltd | 10% Owner | Buy | 259,163 | $0 |
| 2026-03-19 | Huang James | Director | Sell | 5 | $26 |
| 2026-03-19 | Panacea Innovation Ltd | 10% Owner | Sell | 5 | $26 |
| 2026-03-11 | Nguyen AnhCo | President and CEO | Buy | 81,100 | $0 |
| 2026-03-11 | Grant-Huerta Yanina | Chief Accounting Officer | Buy | 20,300 | $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 |
Source: SEC Form 4 filings · as of 2026-09-04