Institutional Ownership
Atara Biotherapeutics Inc
CUSIP 046513206COM NEWATRAQ1 2026
13D / 13G Filings
9
Schedule 13D/13G on record
Beneficial Filers
5
Distinct reporting persons
Largest Stake
10.0%
Max % of class reported
Institutional Holders
30
13F filers (latest quarter)
Beneficial Owners — Schedule 13D / 13G
9 filings · latest Nov 14, 2025
| # | Filed | Reporting Person | Form | % of Class | Shares | Filing |
|---|---|---|---|---|---|---|
| 1 | Nov 14, 2025 | Redmile Group, LLC | 13D/A | 9.9% | — | SEC |
| 2 | Nov 14, 2025 | Ecor1 Capital, LLC | 13G/A | 9.9% | — | SEC |
| 3 | May 23, 2025 | Redmile Group, LLC | 13D | 9.9% | — | SEC |
| 4 | May 15, 2025 | Redmile Group, LLC | 13G/A | 9.9% | 601.2K | SEC |
| 5 | Feb 6, 2025 | Panacea Venture Healthcare Fund II, L.P. | 13G | 9.5% | 550.0K | SEC |
| 6 | Nov 14, 2024 | Citadel Advisors LLC | 13G/A | 4.6% | — | SEC |
| 7 | Nov 14, 2024 | Ecor1 Capital, LLC | 13G/A | 10.0% | 493.5K | SEC |
| 8 | Nov 12, 2024 | Vanguard Group Inc | 13G/A | 3.2% | 180.7K | SEC |
| 9 | Nov 4, 2024 | Vanguard Group Inc | 13G/A | 3.2% | 180.7K | SEC |
Top Institutional Holders (13F)
Largest reported positions · latest quarter
| # | Fund | Shares | Value |
|---|---|---|---|
| 1 | Adage Capital Partners Gp, L.L.C. | 700.0K | $3.31M |
| 2 | Redmile Group, LLC | 441.7K | $2.09M |
| 3 | Mackenzie Financial Corp | 313.6K | $1.48M |
| 4 | Point72 Asset Management, L.P. | 194.3K | $918.9K |
| 5 | Ecor1 Capital, LLC | 99.6K | $471.1K |
| 6 | Blackrock, Inc. | 79.0K | $373.8K |
| 7 | Geode Capital Management, LLC | 66.1K | $313.0K |
| 8 | Ubs Group AG | 50.1K | $236.8K |
| 9 | Staley Capital Advisers Inc | 50.0K | $236.5K |
| 10 | Millennium Management LLC | 47.7K | $225.6K |