EcoR1 Capital, LLC
- SEC CIK
- 0001587114
- Latest filing
- Aug 14, 2026
ATRA holding history
Atara Biotherapeutics, Inc. in every 13F filed by EcoR1 Capital, LLC, including the quarters it was sold out or no filing was made. Changes compare share counts with the previous calendar quarter.
ATRA overviewAll 13F holders of ATRAFull Q2 2026 holdings
- Shares (Q2 2026)
- 1,552,000
- Value
- $17.8M
- % of portfolio
- 0.9%
- Quarters held
- 11
- Since Q4 2023
| Quarter | Shares | Value | % of portfolio | Share change | Action | All holders |
|---|---|---|---|---|---|---|
| Q2 2026 | 1,552,000 | $17.8M | 0.9% | +1,452,407+1,458.3% | Added | Holders |
| Q1 2026 | 99,593 | $471.1K | <0.1% | −473,590−82.6% | Reduced | Holders |
| Q4 2025 | 573,183 | $10.4M | 0.5% | 00.0% | Unchanged | Holders |
| Q3 2025 | 573,183 | $8.21M | 0.4% | 00.0% | Unchanged | Holders |
| Q2 2025 | 573,183 | $4.42M | 0.3% | 00.0% | Unchanged | Holders |
| Q1 2025 | 573,183 | $3.40M | 0.2% | +41,049+7.7% | Added | Holders |
| Q4 2024 | 532,134 | $7.08M | 0.3% | +63,196+13.5% | Added | Holders |
| Q3 2024 | 468,938 | $3.81M | 0.1% | +62,259+15.3% | Added | Holders |
| Q2 2024 | 406,679 | $3.46M | 0.1% | 00.0% | UnchangedConverted for a 1-for-25 split | Holders |
| Q1 2024 | 10,167,043 | $7.06M | 0.2% | +100,000+1.0% | Added | Holders |
| Q4 2023 | 10,067,043 | $5.16M | 0.1% | +10,067,043 | New | Holders |