Atara Biotherapeutics
Supports Pierre Fabre’s global EBV-targeted tab-cel program through a lean partner-led operating model.
$9.20
After-hours close+0.07 (+0.77%)
At close$9.13(−1.30%)
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Breakdown13F · Form 4
Institutions 49.59%4.47M sharesInsiders 26.23%2.36M sharesOther 24.18%2.18M shares
Shares outstanding 9.01M · Float 6.00M · 66.6% free float
Institutions13F, as of Jun 30, 2026
36 holders · 4.47M shares · 4 new positions · 16 increased · 8 reduced · 2 closed
| Holder | Shares | % outstanding | Chg q/q | Filed |
|---|---|---|---|---|
| Ecor1 Capital, LLC | 1.55M | 17.22% | +1.45M | Aug 14, 2026 |
| Adage Capital Partners GP, L.L.C. | 850.0K | 9.43% | +150.0K | Aug 14, 2026 |
| Point72 Asset Management, L.P. | 687.7K | 7.63% | +493.5K | Aug 14, 2026 |
| Redmile Group, LLC | 441.7K | 4.90% | 0 | Aug 14, 2026 |
| Vanguard Capital Management LLC | 247.0K | 2.74% | +29.2K | Aug 13, 2026 |
| Mackenzie Financial Corp | 233.2K | 2.59% | −80.4K | Aug 13, 2026 |
| BlackRock, Inc. | 84.5K | 0.94% | +5.4K | Aug 7, 2026 |
| Geode Capital Management, LLC | 75.1K | 0.83% | +9.0K | Aug 12, 2026 |
Beneficial owners13D/G · 5% or more, as filed
| Holder | % of class | Shares | Form | Filed |
|---|---|---|---|---|
| Adiumentum Capital Fund I GP LLCincl. Gregory A. Ciongoli, Adiumentum Capital Fund I LP | 19.99% | 1.37M | 13D | May 16, 2025 ↗ |
| EcoR1 Capital, LLC | 17.40% | 1.55M | 13G | May 7, 2026 ↗ |
| Panacea Innovation Limitedincl. Panacea Venture Healthcare Fund II, L.P., James Huang +3 more | 16.10% | 1.32M | 13D | May 11, 2026 ↗ |
| Redmile Group, LLCincl. Redmile Strategic Long Only Trading Sub, Ltd., Redmile Biopharma Investments II, L.P. +1 more | 9.90% | 951.0K | 13D | Jul 24, 2026 ↗ |
| Adage Capital Management, L.P. | 8.56% | 700.0K | 13G | May 13, 2026 ↗ |
| Point72 Asset Management, L.P. | 6.20% | 526.7K | 13G | May 8, 2026 ↗ |
InsidersForm 4
| Insider | Role | Shares | % outstanding | Filed |
|---|---|---|---|---|
| Adiumentum Capital Fund I LP | director, 10 percent owner, other: See remarks | 1.21M | 13.42% | May 16, 2025 |
| EcoR1 Capital, LLC | 10 percent owner | 1.04M | 11.59% | May 11, 2026 |
| Panacea Innovation Ltd | 10 percent owner | 1.01M | 11.22% | May 11, 2026 |
| Redmile Group, LLC | director | 636.9K | 7.07% | Jul 24, 2026 |
| AnhCo Nguyen | director, officer: President and CEO | 132.8K | 1.47% | Aug 26, 2026 |
| Pascal Touchon | director | 78.0K | 0.87% | Jun 12, 2025 |
| Eric J. Hyllengren | officer: EVP, CFO and COO | 56.2K | 0.62% | Mar 5, 2025 |
| Yanina Grant-Huerta | officer: Chief Accounting Officer | 49.6K | 0.55% | May 20, 2026 |
| Brian N. Cherry | director | 38.3K | 0.43% | Jun 15, 2026 |
| William K. Heiden | director | 34.2K | 0.38% | Jun 11, 2026 |
6 ten-percent owners hold 2.13M shares by Form 4 — the 13D/G table above shows those stakes, the figure above counts officers and directors only · 21 people have not refiled in the last 18 months (187.2K shares), so they are not in the figure above
Latest trades
| Date | Insider | Type | Shares | Avg price | Owned after |
|---|---|---|---|---|---|
| Aug 17, 2026 | AnhCo Nguyendirector, officer: President and CEO | Sale | 5,062 | $8.08 | 132,775 |
| May 18, 2026 | Yanina Grant-Huertaofficer: Chief Accounting Officer | Sale | 2,414 | $9.13 | 49,636 |
| May 18, 2026 | AnhCo Nguyendirector, officer: President and CEO | Sale | 5,241 | $9.13 | 137,837 |
| May 7, 2026 | EcoR1 Capital, LLC10 percent owner | Purchase | 507,407 | $9.35 | 1,552,000 |
| May 7, 2026 | Panacea Innovation Ltd10 percent owner | Sale | 313,446 | $10.10 | 1,011,000 |
| Mar 2, 2026 | AnhCo Nguyendirector, officer: President and CEO | Sale · 4 lots | 2,996 | $5.09 | 61,978 |
| Mar 2, 2026 | Yanina Grant-Huertaofficer: Chief Accounting Officer | Sale · 4 lots | 2,104 | $5.08 | 31,750 |
| Jan 12, 2026 | Panacea Innovation Ltd10 percent owner | Sale | 80,554 | $6.07 | 1,324,446 |
| Nov 17, 2025 | Yanina Grant-Huertaofficer: Chief Accounting Officer | Sale · 3 lots | 1,804 | $13.19 | 33,454 |
| Nov 17, 2025 | AnhCo Nguyendirector, officer: President and CEO | Sale · 2 lots | 2,915 | $13.19 | 64,974 |
CongressHouse and Senate disclosures
Not reported.