Atara Biotherapeutics
ATRA · NASDAQ
$9.16+$0.20 (+2.23%)TodayMarket closed ·
Prev close $8.96
Who owns ATRA
Largest institutional holders, from their latest 13F filings
The 10 largest institutions hold 75.1% of ATRA’s shares.
- EcoR1 Capital, LLC17.2%
- Panacea Venture14.6%
- Adiumentum Capital Fund I LP14.3%
- Adage Capital Management, L.P.9.4%
- Next 6 largest institutions19.5%
- All other shareholders24.9%
| Holder | Shares | % of shares |
|---|---|---|
| EcoR1 Capital, LLC | 1.55M | 17.23% |
| Panacea Venture | 1.32M | 14.64% |
| Adiumentum Capital Fund I LP | 1.28M | 14.26% |
| Adage Capital Management, L.P. | 850.00K | 9.43% |
| Point72 Asset Management, L.P. | 687.72K | 7.63% |
| Redmile Group, LLC | 441.70K | 4.90% |
| Vanguard Capital Management, LLC | 247.05K | 2.74% |
| Mackenzie Financial Corporation | 233.25K | 2.59% |
| Geode Capital Management, L.L.C. | 75.13K | 0.83% |
| BlackRock Institutional Trust Company, N.A. | 73.05K | 0.81% |
Largest mutual fund holders
| Holder | Shares | % of shares |
|---|---|---|
| Vanguard Total Stock Market Index Fund | 158.65K | 1.76% |
| Mackenzie US Quantitative Small Cap Fund | 89.73K | 1.00% |
| Vanguard Extended Market Index Fund | 82.76K | 0.92% |
| Mackenzie GQE US Small Cap Fund | 66.98K | 0.74% |
| Fidelity Extended Market Index Fund | 35.39K | 0.39% |
Insider trades
Form 4 filings by officers, directors and large holders
Over the last 6 months, insiders bought $5.74M (2 trades) and sold $3.28M (4 trades) of ATRA on the open market.
| Insider | Type | Shares | Value |
|---|---|---|---|
| Cherry Brian N | Buy | 104.17K | $999.99K |
| Nguyen AnhCo | Sale | 5.06K | $40.88K |
| Redmile Group, LLC | Option exercise | 55.39K | — |
| Redmile Group, LLC | Option exercise | 38.73K | — |
| Redmile Group, LLC | Option exercise | 101.09K | — |
| Redmile Group, LLC | Tax withholding | 60 | — |
| Redmile Group, LLC | Option exercise | 195.21K | — |
| Cherry Brian N | Award | 24.00K | — |
| Ciongoli Gregory Austin | Award | 12.00K | — |
| Fust Matthew K | Award | 12.00K | — |
Short interest
Settled Sep 30, 2026
- Shares short
- 321.79K
- Days to cover
- 8.11
- % of shares outstanding
- 3.57%
- Average daily volume
- 39.66K
- Change since last report
- −20.4%
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