EcoR1 Capital, LLC
In its 13F for Q4 2025 (holdings as of December 31, 2025, filed February 17, 2026), EcoR1 Capital, LLC reported 26 stock positions worth $2.2 billion. Its top holding was Zymeworks (ZYME) at 27.7% of the portfolio, followed by Anaptysbio (ANAB, 17.5%) and Jazz Pharmaceuticals (JAZZ, 13.3%). Compared with Q3 2025, it opened 9 new positions, sold out of 11, added to 2 and reduced 2. The biggest buy was Centessa Pharmaceuticals (CNTA, shares +466%) and the biggest sale an exit from Uniqure (QURE).
- Most Recent 13F
- Q2 2026
- Location
- San Francisco, CA
- CIK
- 0001587114
- Portfolio Value
- $2.2B (Q4 2025)
- SEC Filing
- 0000935836-26-000101 ↗ filed Feb 17, 2026
Holdings Value
Holdings 26 stocks · $2.2B
| ZYME Zymeworks Inc. | 27.72% | 22,970,388 | $604.8M | No change |
| ANAB Anaptysbio Inc. | 17.51% | 7,880,094 | $382.0M | No change |
| JAZZ Jazz Pharmaceuticals PLC | 13.29% | 1,706,469 | $290.1M | No change |
| CRNX Crinetics Pharmaceuticals Inc. | 9.15% | 4,288,120 | $199.6M | No change |
| CNTA Centessa Pharmaceuticals Ltd. | 3.57% | 3,115,000 | $77.9M | Add +466.4% |
| CRSP Crispr Therapeutics AG | 3.34% | 1,389,276 | $72.9M | No change |
| MBX MBX Biosciences Inc. | 3.07% | 2,123,604 | $67.0M | No change |
| IMNM Immunome Inc. | 2.81% | 2,855,590 | $61.3M | Reduce -30.0% |
| ORIC Oric Pharmaceuticals Inc. | 2.52% | 6,728,116 | $55.0M | No change |
| LKFT Lakefront Biotherapeutic-ADR filed as GALAPAGOS NV | 2.50% | 1,667,119 | $54.5M | No change |
| XNCR Xencor Inc. | 2.28% | 3,251,112 | $49.8M | Reduce -47.1% |
| BBOT Bridgebio Oncology Therapeut | 1.62% | 2,823,126 | $35.3M | No change |
| ETON Eton Pharmaceuticals Inc. | 1.57% | 2,030,544 | $34.3M | No change |
| CGON CG Oncology Inc. | 1.47% | 772,000 | $32.1M | New |
| ZBIO Zenas Biopharma Inc. | 1.31% | 789,500 | $28.7M | New |
| NGNE Neurogene Inc. | 1.20% | 1,271,342 | $26.2M | No change |
| GPCR Structure Therapeutics Inc. | 1.07% | 334,380 | $23.3M | New |
| PCVX Vaxcyte Inc. | 0.95% | 450,000 | $20.8M | New |
| AQST Aquestive Therapeutics Inc. | 0.78% | 2,625,000 | $17.0M | No change |
| VYGR Voyager Therapeutics Inc. | 0.72% | 4,002,847 | $15.7M | Add +497.2% |
| ATRA Atara Biotherapeutics Inc. | 0.48% | 573,183 | $10.4M | No change |
| MNKD Mannkind Corp. | 0.43% | 1,660,000 | $9.4M | New |
| EOLS Evolus Inc. | 0.21% | 675,000 | $4.5M | New |
| IBIO Ibio Inc. | 0.20% | 2,228,000 | $4.3M | New |
| MREO Mereo Biopharma Group PL-ADR | 0.15% | 7,856,466 | $3.3M | New |
| CAMP CAMP4 Therapeutics Corp. | 0.09% | 325,000 | $2.0M | New |
Options reported separately and not counted above: CGON calls ($12.2M), XNCR calls ($1.0M).
Other holdings (2): bonds, preferreds, convertibles and warrants · $8.7M (not counted above)
Total filed on the 13F, all lines: $2.2B.
Portfolio Sells Q3 2025 → Q4 2025
| QURE Uniqure NV | Sold out | 0.00% | −11.20 |
| TNGX Tango Therapeutics Inc. | Sold out | 0.00% | −4.29 |
| APLS Apellis Pharmaceuticals Inc. | Sold out | 0.00% | −3.75 |
| MDGL Madrigal Pharmaceuticals Inc. | Sold out | 0.00% | −1.65 |
| RNAM Avidity Biosciences Inc. | Sold out | 0.00% | −1.60 |
| XNCR Xencor Inc. | Reduce -47.1% | 2.28% | −1.19 |
| ALKS Alkermes PLC | Sold out | 0.00% | −0.72 |
| MTSR Metsera Inc. | Sold out | 0.00% | −0.68 |
| PRME Prime Medicine Inc. | Sold out | 0.00% | −0.41 |
| KURA Kura Oncology Inc. | Sold out | 0.00% | −0.37 |
| PEPG Pepgen Inc. | Sold out | 0.00% | −0.18 |
| CMPS Compass Pathways PLC | Sold out | 0.00% | −0.07 |
| IMNM Immunome Inc. | Reduce -30.0% | 2.81% | +0.51 |
Portfolio Buys Q3 2025 → Q4 2025
| CNTA Centessa Pharmaceuticals Ltd. | Add +466.4% | 3.57% | +2.93 |
| CGON CG Oncology Inc. | New | 1.47% | +1.47 |
| ZBIO Zenas Biopharma Inc. | New | 1.31% | +1.31 |
| GPCR Structure Therapeutics Inc. | New | 1.07% | +1.07 |
| PCVX Vaxcyte Inc. | New | 0.95% | +0.95 |
| VYGR Voyager Therapeutics Inc. | Add +497.2% | 0.72% | +0.57 |
| MNKD Mannkind Corp. | New | 0.43% | +0.43 |
| EOLS Evolus Inc. | New | 0.21% | +0.21 |
| IBIO Ibio Inc. | New | 0.20% | +0.20 |
| MREO Mereo Biopharma Group PL-ADR | New | 0.15% | +0.15 |
| CAMP CAMP4 Therapeutics Corp. | New | 0.09% | +0.09 |
Options Activity Q3 2025 → Q4 2025
Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.
Notes & Other Activity Q3 2025 → Q4 2025
| SRZNW Surrozen Inc.-CW25 | *W EXP 08/01/203 | Reduce -93.3% | 4,444 | $100K |
Bonds, preferreds, convertibles and warrants; not part of the stock holdings or percentages above.
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 30 | $2.0B | ZYME, ANAB, AKTS, CGON, ETON |
| Q1 2026 | 28 | $2.3B | ZYME, ANAB, JAZZ, CNTA, CRNX |
| Q4 2025 | 26 | $2.2B | ZYME, ANAB, JAZZ, CRNX, CNTA |
| Q3 2025 | 28 | $2.1B | ZYME, ANAB, QURE, JAZZ, CRNX |
| Q2 2025 | 34 | $1.7B | ZYME, APLS, JAZZ, ANAB, CRNX |
| Q1 2025 | 42 | $1.7B | APLS, JAZZ, ZYME, ANAB, CRNX |
| Q4 2024 | 53 | $2.5B | APLS, ZYME, CRNX, JAZZ, PRTA |
| Q3 2024 | 60 | $2.9B | APLS, ANAB, CRNX, PRTA, JAZZ |
| Q2 2024 | 52 | $3.3B | APLS, PRTA, SRPT, ANAB, CRNX |
| Q1 2024 | 54 | $3.9B | APLS, PRTA, ARVN, SRPT, CRNX |