| $350M | ||
| $217M | ||
| $172M | ||
| $109M | ||
| $107M | ||
| $104M |
Buys | $5,744,249 | 2 | 18 |
Sells | $3,852,958 | 9 | 82 |
| EcoR1 Capital, LLC | 10 percent owner | 1 | $4.74M | 0 | $0 | $4.74M |
| Cherry Brian N | director | 1 | $999,994 | 0 | $0 | $999,994 |
| Grant-Huerta Yanina | Chief Accounting Officer | 0 | $0 | 3 | $56,515 | $-56,515 |
| Nguyen AnhCo | President and CEO | 0 | $0 | 4 | $142,402 | $-142,402 |
| Panacea Innovation Ltd | 10 percent owner | 0 | $0 | 2 | $3.65M | $-3.65M |
Founded in 2012 and headquartered in South San Francisco, California, Atara Biotherapeutics, Inc. is dedicated to pioneering ready-to-use (off-the-shelf) T-cell immunotherapies. Their primary focus in the United States involves creating treatments for patients battling cancer, autoimmune disorders, and viral infections. A key therapeutic candidate, tabelecleucel, is currently undergoing Phase 3 clinical trials for Epstein-Barr virus (EBV)-driven post-transplant lymphoproliferative disease, as well as various hematologic and solid tumors, such …
Over the last 12 months, insiders at Atara Biotherapeutics, Inc. have bought $5.74M and sold $3.85M worth of Atara Biotherapeutics, Inc. stock.
On average, over the past 5 years, insiders at Atara Biotherapeutics, Inc. have bought $2.27M and sold $1.27M worth of stock each year.
Highest buying activity among insiders over the last 12 months: EcoR1 Capital, LLC (10 percent owner) — $4.74M. Cherry Brian N (director) — $999,994.
The last purchase of 104,166 shares for transaction amount of $999,994 was made by Cherry Brian N (director) on 2026‑09‑04.
| 2026-09-04 | Cherry Brian N | director | 104,166 1.1371% | $9.60 | $999,994 | -5.23% | ||
| 2026-08-17 | Sale | Nguyen AnhCo | President and CEO | 5,062 0.0325% | $8.08 | $40,883 | +11.84% | |
| 2026-05-18 | Sale | Nguyen AnhCo | President and CEO | 5,241 0.0614% | $9.13 | $47,845 | +2.51% | |
| 2026-05-18 | Sale | Grant-Huerta Yanina | Chief Accounting Officer | 2,414 0.0283% | $9.13 | $22,036 | +2.51% | |
| 2026-05-07 | Sale | Panacea Innovation Ltd | 10 percent owner | 313,446 3.7444% | $10.10 | $3.17M | -5.54% | |
| 2026-05-07 | EcoR1 Capital, LLC | 10 percent owner | 507,407 5.6127% | $9.35 | $4.74M | -5.54% | ||
| 2026-03-02 | Sale | Nguyen AnhCo | President and CEO | 2,996 0.039% | $5.09 | $15,237 | +78.62% | |
| 2026-03-02 | Sale | Grant-Huerta Yanina | Chief Accounting Officer | 2,104 0.0274% | $5.08 | $10,691 | +78.62% | |
| 2026-01-12 | Sale | Panacea Innovation Ltd | 10 percent owner | 80,554 1.1536% | $6.07 | $489,019 | +44.05% | |
| 2025-11-17 | Sale | Nguyen AnhCo | President and CEO | 2,915 0.0418% | $13.19 | $38,437 | -32.98% | |
| 2025-11-17 | Sale | Grant-Huerta Yanina | Chief Accounting Officer | 1,804 0.0259% | $13.19 | $23,788 | -32.98% | |
| 2025-08-18 | Sale | Nguyen AnhCo | President and CEO | 2,958 0.0426% | $11.62 | $34,360 | -14.11% | |
| 2025-08-18 | Sale | Grant-Huerta Yanina | Chief Accounting Officer | 1,809 0.0261% | $11.61 | $21,009 | -14.11% | |
| 2025-08-15 | Panacea Innovation Ltd | 10 percent owner | 55,000 0.7767% | $12.19 | $670,423 | -19.37% | ||
| 2025-07-17 | Panacea Innovation Ltd | 10 percent owner | 19,335 0.2955% | $9.64 | $186,372 | +12.05% | ||
| 2025-05-16 | Sale | Nguyen AnhCo | President and CEO | 3,276 0.0543% | $6.76 | $22,156 | +42.69% | |
| 2025-05-16 | Sale | Grant-Huerta Yanina | Chief Accounting Officer | 2,218 0.0368% | $6.76 | $15,000 | +42.69% | |
| 2025-03-03 | Sale | Nguyen AnhCo | President and CEO | 3,331 0.0578% | $7.00 | $23,307 | +32.57% | |
| 2025-03-03 | Sale | Hyllengren Eric J | EVP, CFO and COO | 1,211 0.021% | $7.00 | $8,473 | +32.57% | |
| 2025-03-03 | Sale | Henrich Jill | EVP, Chief Regulatory Officer | 1,059 0.0184% | $7.00 | $7,410 | +32.57% |
| EcoR1 Capital, LLC | 10 percent owner | 1552000 15.4617% | $12.73M | 1 | 0 | |
| Panacea Innovation Ltd | 10 percent owner | 1011000 10.072% | $8.29M | 2 | 2 | <0.0001% |
| Cherry Brian N | director | 166486 1.6586% | $1.37M | 1 | 0 | |
| Domain Partners VIII, L.P. | 10 percent owner | 2141542 21.335% | $17.56M | 1 | 0 | +169.68% |
| MARCUS JOEL S | director | 888355 8.8502% | $7.28M | 3 | 3 | +73.99% |
| DOBMEIER ERIC | director | 563325 5.6121% | $4.62M | 4 | 0 | +27.89% |
| Gallagher Carol Giltner | director | 459418 4.5769% | $3.77M | 4 | 18 | +108.51% |
| HEIDEN WILLIAM K | director | 209000 2.0822% | $1.71M | 1 | 0 | +141.65% |
| Koppikar Utpal | Chief Financial Officer | 181978 1.8129% | $1.49M | 1 | 21 | <0.0001% |
| Yarema Kristin | Chief Commercial Officer | 125882 1.2541% | $1.03M | 2 | 1 | +0.58% |
| DP VIII Associates, L.P. | 10 percent owner | 15890 0.1583% | $130,298.00 | 1 | 0 | +169.68% |
$9,405,928 | 107 | 12.61% | $74.85M | |
$1,701,941 | 56 | 17.58% | $93.09M | |
$66,137,559 | 49 | 6.29% | $89.66M | |
$77,146,704 | 43 | 13.28% | $93.12M | |
$26,786,140 | 22 | -18.62% | $78.7M |
| Increased Positions | 19 | +50% | 247,396 | +13.14% |
| Decreased Positions | 12 | -31.58% | 80,904 | -4.3% |
| New Positions | 7 | New | 80,664 | New |
| Sold Out Positions | 4 | Sold Out | 26,412 | Sold Out |
| Total Postitions | 45 | +18.42% | 2M | +8.84% |
| Ecor1 Capital, Llc | $10,185.00 | 8.19% | 573,183 | 0 | 0% | 2025-09-30 |
| Redmile Group, Llc | $7,849.00 | 6.31% | 441,701 | 0 | 0% | 2025-09-30 |
| Vanguard Group Inc | $3,615.00 | 2.91% | 203,438 | +12,677 | +6.64% | 2025-09-30 |
| Marshall Wace, Llp | $2,058.00 | 1.65% | 115,796 | +73,441 | +173.39% | 2025-09-30 |
| Blackrock, Inc. | $1,241.00 | 1% | 69,833 | -1,015 | -1.43% | 2025-09-30 |
| Mackenzie Financial Corp | $1,134.00 | 0.91% | 63,816 | +41,302 | +183.45% | 2025-09-30 |
| Geode Capital Management, Llc | $1,076.00 | 0.87% | 60,526 | +390 | +0.65% | 2025-09-30 |
| Acadian Asset Management Llc | $1,003.00 | 0.81% | 56,416 | -8,739 | -13.41% | 2025-09-30 |
| Staley Capital Advisers Inc | $889.00 | 0.71% | 50,000 | -25,000 | -33.33% | 2025-09-30 |
| Morgan Stanley | $639.00 | 0.51% | 35,938 | +21,012 | +140.77% | 2025-09-30 |