| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| Redmile Group, LLC | 9.9% | 0% | $10,764,875 | +$659,400 | 751,223 | +6.5% | Redmile Group, LLC | 12 Nov 2025 |
| EcoR1 Capital, LLC | 9.9% | $10,258,030 | 715,853 | EcoR1 Capital, LLC | 30 Sep 2025 | |||
| Panacea Innovation Ltd | 9.5% | $4,180,000 | 550,000 | Panacea Venture Healthcare Fund II, L.P. | 30 Jan 2025 |
As of 30 Sep 2025, 36 institutional investors reported holding 1,883,136 shares of Atara Biotherapeutics, Inc. - Common Stock (ATRA). This represents 26% of the company’s total 7,230,838 outstanding shares.
The largest institutional shareholders of Atara Biotherapeutics, Inc. - Common Stock (ATRA) together control 26% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| EcoR1 Capital, LLC | 7.9% | 573,183 | 0% | 0.39% | $8,213,712 |
| Redmile Group, LLC | 6.1% | 441,701 | 0% | 0.62% | $6,329,575 |
| VANGUARD GROUP INC | 2.8% | 203,438 | +6.6% | 0% | $2,915,266 |
| MARSHALL WACE, LLP | 1.6% | 115,796 | +173% | 0% | $1,659,357 |
| BlackRock, Inc. | 0.97% | 69,833 | -1.4% | 0% | $1,000,706 |
| MACKENZIE FINANCIAL CORP | 0.88% | 63,816 | +183% | 0% | $914,483 |
| GEODE CAPITAL MANAGEMENT, LLC | 0.84% | 60,526 | +0.65% | 0% | $867,499 |
| ACADIAN ASSET MANAGEMENT LLC | 0.78% | 56,416 | -13% | 0% | $807,000 |
| STALEY CAPITAL ADVISERS INC | 0.69% | 50,000 | -33% | 0.03% | $716,500 |
| MORGAN STANLEY | 0.5% | 35,938 | +141% | 0% | $514,991 |
| GSA CAPITAL PARTNERS LLP | 0.36% | 26,213 | +34% | 0.03% | $376,000 |
| STATE STREET CORP | 0.35% | 25,253 | 0% | 0% | $361,875 |
| JANE STREET GROUP, LLC | 0.31% | 22,060 | 0% | $316,120 | |
| RENAISSANCE TECHNOLOGIES LLC | 0.26% | 18,936 | +12% | 0% | $271,353 |
| UBS Group AG | 0.24% | 17,268 | +106% | 0% | $247,451 |
| FMR LLC | 0.24% | 17,156 | 0% | 0% | $245,845 |
| Cambridge Investment Research Advisors, Inc. | 0.24% | 17,109 | 0% | $245,000 | |
| Quadrature Capital Ltd | 0.23% | 16,542 | 0% | $236,881 | |
| GLOBEFLEX CAPITAL L P | 0.21% | 15,458 | 0.03% | $221,513 | |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | 0.19% | 14,000 | 0% | 0% | $200,620 |
| NORTHERN TRUST CORP | 0.15% | 11,033 | -1.2% | 0% | $158,103 |
| BANK OF AMERICA CORP /DE/ | 0.08% | 5,845 | -24% | 0% | $83,758 |
| SBI Securities Co., Ltd. | 0.02% | 1,404 | 0% | 0% | $20,119 |
| ROYAL BANK OF CANADA | 0.02% | 1,209 | -17% | 0% | $17,000 |
| Private Wealth Asset Management, LLC | 0.01% | 900 | 0% | $12,897 |
| Period | Reported Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2025 Q3 | 1,883,136 | $26,983,314 | +$1,944,887 | $14.33 | 36 |
| 2025 Q2 | 1,803,350 | $13,921,685 | -$1,938,164 | $7.72 | 32 |
| 2025 Q1 | 2,086,793 | $12,393,904 | -$4,023,428 | $5.94 | 36 |
| 2024 Q4 | 2,368,286 | $31,519,295 | -$410,987 | $13.31 | 41 |
| 2024 Q3 | 2,414,500 | $19,628,975 | -$1,762,796 | $8.13 | 33 |
| 2024 Q2 | 2,653,675 | $22,554,322 | +$22,225,788 | $8.50 | 43 |