ATRA Atara Biotherapeutics, Inc.: institutional ownership and insider trading
38 funds reported holding $55.4M of Atara Biotherapeutics, Inc. in their latest 13F filings; in Q2 2026 funds net bought $21.9M, with 4 new positions and 1 funds selling out; over the last 12 months insiders bought $5.74M and sold $3.85M on the open market.
Famous investors holding ATRA
- Izzy Englander (Millennium Management): $146K, 0.0% of the portfolio
- Ken Griffin (Citadel Advisors): $117K, 0.0% of the portfolio
Largest institutional holders of ATRA
- EcoR1 Capital, LLC — $17.8M
- ADAGE CAPITAL PARTNERS GP, L.L.C. — $9.76M
- Point72 Asset Management, L.P. — $7.90M
- Redmile Group, LLC — $5.07M
- VANGUARD GROUP INC — $4.09M
- VANGUARD CAPITAL MANAGEMENT LLC — $2.84M
- MACKENZIE FINANCIAL CORP — $2.68M
- BlackRock, Inc. (BLK) — $970K
- GEODE CAPITAL MANAGEMENT, LLC — $863K
- STALEY CAPITAL ADVISERS INC — $574K
Recent ATRA insider trades
- Sep 4, 2026: Cherry Brian N bought 104,166 shares ($1000K)
- Aug 17, 2026: Nguyen AnhCo sold 5,062 shares ($40.9K)
- May 18, 2026: Grant-Huerta Yanina sold 2,414 shares ($22.0K)
- May 18, 2026: Nguyen AnhCo sold 5,241 shares ($47.9K)
5%+ owners
- EcoR1 Capital, LLC: 17.4% (Schedule 13G/A, filed May 7, 2026)
- Redmile Group, LLC: 9.9% (Schedule 13D/A, filed Jul 24, 2026)
- Adage Capital Management, L.P.: 8.6% (Schedule 13G, filed May 13, 2026)
- Point72 Asset Management, L.P.: 7.6% (Schedule 13G/A, filed Aug 14, 2026)