EcoR1 Capital, LLC

In its 13F for Q3 2025 (holdings as of September 30, 2025, filed November 14, 2025), EcoR1 Capital, LLC reported 28 stock positions worth $2.1 billion. Its top holding was Zymeworks (ZYME) at 18.9% of the portfolio, followed by Anaptysbio (ANAB, 11.6%) and Uniqure (QURE, 11.2%). Compared with Q2 2025, it opened 6 new positions, sold out of 12, added to 4 and reduced 3. The biggest buy was Oric Pharmaceuticals (ORIC, shares +316%) and the biggest sale Apellis Pharmaceuticals (APLS, shares −71%).

Most Recent 13F
Q2 2026
Location
San Francisco, CA
CIK
0001587114
Portfolio Value
$2.1B (Q3 2025)
SEC Filing
0000935836-25-000671 ↗ filed Nov 14, 2025

Holdings Value

0$1.0B$2.0B$3.0B$4.0B Q1 2024: $3.9B Q1 2024 Q2 2024: $3.3B Q2 2024 Q3 2024: $2.9B Q3 2024 Q4 2024: $2.5B Q4 2024 Q1 2025: $1.7B Q1 2025 Q2 2025: $1.7B Q2 2025 Q3 2025: $2.1B $2.1B Q3 2025 Q4 2025: $2.2B Q4 2025 Q1 2026: $2.3B Q1 2026 Q2 2026: $2.0B Q2 2026

Holdings 28 stocks · $2.1B
ZYME Zymeworks Inc. 18.87% 22,970,388 $392.3M No change
ANAB Anaptysbio Inc. 11.60% 7,880,094 $241.3M No change
QURE Uniqure NV 11.20% 3,988,971 $232.8M No change
JAZZ Jazz Pharmaceuticals PLC 10.82% 1,706,469 $224.9M No change
CRNX Crinetics Pharmaceuticals Inc. 8.59% 4,288,120 $178.6M No change
CRSP Crispr Therapeutics AG 4.33% 1,389,276 $90.0M No change
TNGX Tango Therapeutics Inc. 4.29% 10,630,736 $89.3M No change
ORIC Oric Pharmaceuticals Inc. 3.88% 6,728,116 $80.7M Add +315.8%
APLS Apellis Pharmaceuticals Inc. 3.75% 3,447,156 $78.0M Reduce -71.0%
XNCR Xencor Inc. 3.47% 6,144,767 $72.1M No change
LKFT Lakefront Biotherapeutic-ADR filed as GALAPAGOS NV 2.78% 1,667,119 $57.7M Add +60.8%
IMNM Immunome Inc. 2.30% 4,079,415 $47.8M No change
ETON Eton Pharmaceuticals Inc. 2.12% 2,030,544 $44.1M No change
MBX MBX Biosciences Inc. 1.79% 2,123,604 $37.2M Add +84.7%
MDGL Madrigal Pharmaceuticals Inc. 1.65% 75,000 $34.4M No change
RNAM Avidity Biosciences Inc. 1.60% 765,000 $33.3M Add +53.0%
BBOT Bridgebio Oncology Therapeut 1.57% 2,823,126 $32.7M New
NGNE Neurogene Inc. 1.06% 1,271,342 $22.0M No change
ALKS Alkermes PLC 0.72% 500,000 $15.0M No change
AQST Aquestive Therapeutics Inc. 0.71% 2,625,000 $14.7M New
MTSR Metsera Inc. 0.68% 271,529 $14.2M No change
CNTA Centessa Pharmaceuticals Ltd. 0.64% 550,000 $13.3M New
PRME Prime Medicine Inc. 0.41% 1,543,326 $8.6M New
ATRA Atara Biotherapeutics Inc. 0.40% 573,183 $8.2M No change
KURA Kura Oncology Inc. 0.37% 872,500 $7.7M Reduce -79.2%
PEPG Pepgen Inc. 0.18% 800,000 $3.7M New
VYGR Voyager Therapeutics Inc. 0.15% 670,303 $3.1M Reduce -82.9%
CMPS Compass Pathways PLC 0.07% 265,137 $1.5M New
Other holdings (2): bonds, preferreds, convertibles and warrants · $4.4M (not counted above)
SecurityClassShares / PrincipalValueChange
NUVB.WS Nuvation Bio Inc. -CW27 *W EXP 02/10/202 963,333$3.6MNo change
SRZNW Surrozen Inc.-CW25 *W EXP 08/01/203 66,665$859KNo change

Total filed on the 13F, all lines: $2.1B.

Portfolio Sells Q2 2025 → Q3 2025
APLS Apellis Pharmaceuticals Inc. Reduce -71.0% 3.75% −8.47
ITOS Iteos Therapeutics Inc. Sold out 0.00% −6.32
JANX Janux Therapeutics Inc. Sold out 0.00% −2.02
AKRO Akero Therapeutics Inc. Sold out 0.00% −1.39
VRNA Verona Pharma Ltd. Sold out 0.00% −1.12
TECX Tectonic Therapeutic Inc. Sold out 0.00% −1.10
KURA Kura Oncology Inc. Reduce -79.2% 0.37% −1.07
PCRX Pacira Biosciences Inc. Sold out 0.00% −0.65
VYGR Voyager Therapeutics Inc. Reduce -82.9% 0.15% −0.57
REPL Replimune Group Inc. Sold out 0.00% −0.47
ADAPY Adaptimmune Therapeutics-ADR Sold out 0.00% −0.39
DAWN Day One Biopharmaceuticals I Sold out 0.00% −0.33
HLVX Hillevax Inc. Sold out 0.00% −0.29
WHWK Whitehawk Therapeutics Inc. Sold out 0.00% −0.12
MGNX Macrogenics Inc. Sold out 0.00% −0.12

Portfolio Buys Q2 2025 → Q3 2025
ORIC Oric Pharmaceuticals Inc. Add +315.8% 3.88% +2.91
BBOT Bridgebio Oncology Therapeut New 1.57% +1.57
LKFT Lakefront Biotherapeutic-ADR Add +60.8% 2.78% +1.05
MBX MBX Biosciences Inc. Add +84.7% 1.79% +1.01
RNAM Avidity Biosciences Inc. Add +53.0% 1.60% +0.76
AQST Aquestive Therapeutics Inc. New 0.71% +0.71
CNTA Centessa Pharmaceuticals Ltd. New 0.64% +0.64
PRME Prime Medicine Inc. New 0.41% +0.41
PEPG Pepgen Inc. New 0.18% +0.18
CMPS Compass Pathways PLC New 0.07% +0.07

Options Activity Q2 2025 → Q3 2025
QURE Uniqure NV call Sold out 135,000 $1.9Mbefore exit

Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.

All Filings

QuarterPositions13F Reported ValueTop Holdings
Q2 2026 30$2.0BZYME, ANAB, AKTS, CGON, ETON
Q1 2026 28$2.3BZYME, ANAB, JAZZ, CNTA, CRNX
Q4 2025 26$2.2BZYME, ANAB, JAZZ, CRNX, CNTA
Q3 2025 28$2.1BZYME, ANAB, QURE, JAZZ, CRNX
Q2 2025 34$1.7BZYME, APLS, JAZZ, ANAB, CRNX
Q1 2025 42$1.7BAPLS, JAZZ, ZYME, ANAB, CRNX
Q4 2024 53$2.5BAPLS, ZYME, CRNX, JAZZ, PRTA
Q3 2024 60$2.9BAPLS, ANAB, CRNX, PRTA, JAZZ
Q2 2024 52$3.3BAPLS, PRTA, SRPT, ANAB, CRNX
Q1 2024 54$3.9BAPLS, PRTA, ARVN, SRPT, CRNX