EcoR1 Capital, LLC

In its 13F for Q3 2024 (holdings as of September 30, 2024, filed November 14, 2024), EcoR1 Capital, LLC reported 60 stock positions worth $2.9 billion. Its top holding was Apellis Pharmaceuticals (APLS) at 11.8% of the portfolio, followed by Anaptysbio (ANAB, 9.0%) and Crinetics Pharmaceuticals (CRNX, 7.5%). Compared with Q2 2024, it opened 12 new positions, sold out of 4, added to 7 and reduced 5. The biggest buy was Jazz Pharmaceuticals (JAZZ, shares +68%) and the biggest sale an exit from Sarepta Therapeutics (SRPT).

Most Recent 13F
Q2 2026
Location
San Francisco, CA
CIK
0001587114
Portfolio Value
$2.9B (Q3 2024)
SEC Filing
0000935836-24-000682 ↗ filed Nov 14, 2024

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 $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 Q3 2025 Q4 2025: $2.2B Q4 2025 Q1 2026: $2.3B Q1 2026 Q2 2026: $2.0B Q2 2026

Holdings 60 stocks · $2.9B
APLS Apellis Pharmaceuticals Inc. 11.76% 11,890,843 $342.9M Add +2.4%
ANAB Anaptysbio Inc. 8.95% 7,794,996 $261.1M Add +3.6%
CRNX Crinetics Pharmaceuticals Inc. 7.51% 4,288,120 $219.1M Add +3.2%
PRTA Prothena Corp. PLC 6.64% 11,584,280 $193.8M No change
JAZZ Jazz Pharmaceuticals PLC 6.52% 1,706,469 $190.1M Add +68.3%
ZYME Zymeworks Inc. 5.78% 13,437,473 $168.6M No change
ARVN Arvinas Inc. 5.68% 6,726,491 $165.7M No change
KURA Kura Oncology Inc. 3.89% 5,806,871 $113.5M No change
XNCR Xencor Inc. 3.67% 5,330,416 $107.2M No change
TNGX Tango Therapeutics Inc. 3.52% 13,330,736 $102.6M No change
JANX Janux Therapeutics Inc. 2.29% 1,469,818 $66.8M No change
CRSP Crispr Therapeutics AG 2.24% 1,389,276 $65.3M No change
IMNM Immunome Inc. 1.94% 3,879,415 $56.7M No change
NGNE Neurogene Inc. 1.83% 1,271,342 $53.3M No change
CNTA Centessa Pharmaceuticals Ltd. 1.77% 3,223,851 $51.5M Reduce -43.6%
VRDN Viridian Therapeutics Inc. 1.53% 1,958,847 $44.6M New
NUVB Nuvation Bio Inc. 1.51% 19,209,643 $44.0M No change
THRD Third Harmonic Bio Inc. 1.48% 3,182,444 $43.1M No change
PCVX Vaxcyte Inc. 1.38% 352,464 $40.3M Add +17.5%
MERSANA THERAPEUTICS INC 1.25% 19,364,688 $36.6M No change
ORIC Oric Pharmaceuticals Inc. 1.20% 3,418,068 $35.0M No change
RNAM Avidity Biosciences Inc. 1.19% 757,576 $34.8M No change
EWTX Edgewise Therapeutics Inc. 1.14% 1,250,385 $33.4M No change
MBX MBX Biosciences Inc. 1.05% 1,175,809 $30.5M New
NMRA Neumora Therapeutics Inc. 0.94% 2,071,450 $27.4M No change
CRGX Cargo Therapeutics Inc. 0.93% 1,470,000 $27.1M No change
ADAPY Adaptimmune Therapeutics-ADR 0.89% 27,404,070 $26.0M No change
TECX Tectonic Therapeutic Inc. 0.88% 849,143 $25.7M No change
TCRX Tscan Therapeutics Inc. 0.85% 5,000,000 $24.9M No change
VYGR Voyager Therapeutics Inc. 0.79% 3,917,546 $22.9M No change
CLDX Celldex Therapeutics Inc. 0.76% 650,000 $22.1M No change
BCYC Bicycle Therapeutics PLC-ADR 0.71% 910,000 $20.6M No change
IONS Ionis Pharmaceuticals Inc. 0.69% 500,000 $20.0M New
DYN Dyne Therapeutics Inc. 0.68% 555,644 $20.0M Add +30.1%
AVIR Atea Pharmaceuticals Inc. 0.63% 5,441,896 $18.2M No change
RLAY Relay Therapeutics Inc. 0.61% 2,500,000 $17.7M New
PHVS Pharvaris NV 0.57% 900,000 $16.7M No change
ITOS Iteos Therapeutics Inc. 0.56% 1,608,616 $16.4M Reduce -50.5%
MDGL Madrigal Pharmaceuticals Inc. 0.55% 75,000 $15.9M No change
DAWN Day One Biopharmaceuticals I 0.41% 862,068 $12.0M New
KROS Keros Therapeutics Inc. 0.37% 187,500 $10.9M No change
REPL Replimune Group Inc. 0.32% 850,341 $9.3M No change
ALLOVIR INC 0.31% 11,294,585 $9.1M No change
LENZ Lenz Therapeutics Inc. 0.28% 346,772 $8.2M Reduce -71.6%
VERV Verve Therapeutics Inc. 0.21% 1,250,000 $6.0M No change
GBIO Generation Bio Co. 0.17% 2,046,867 $5.1M No change
LKFT Lakefront Biotherapeutic-ADR filed as GALAPAGOS NV 0.15% 155,006 $4.5M Reduce -97.3%
BBIO Bridgebio Pharma Inc. 0.15% 170,172 $4.3M New
ATRA Atara Biotherapeutics Inc. 0.13% 468,938 $3.8M Add +15.3%
WHWK Whitehawk Therapeutics Inc. filed as AADI BIOSCIENCE INC 0.13% 1,845,253 $3.8M New
ETON Eton Pharmaceuticals Inc. 0.12% 566,075 $3.4M New
PRQR Proqr Therapeutics NV 0.11% 1,835,991 $3.3M Reduce -10.1%
PRME Prime Medicine Inc. 0.09% 700,000 $2.7M No change
HOOK Hookipa Pharma Inc. 0.08% 571,727 $2.5M No change
ALGS Aligos Therapeutics Inc. 0.08% 255,573 $2.2M No change
KYTX Kyverna Therapeutics Inc. 0.08% 450,000 $2.2M No change
ARTV Artiva Biotherapeutics Inc. 0.02% 41,453 $640K New
DSGN Design Therapeutics Inc. 0.01% 53,834 $290K New
MGNX Macrogenics Inc. 0.01% 56,018 $184K New
ALLK Allakos LLC 0.00% 192,346 $126K New

Options reported separately and not counted above: ETON calls ($1.4M).

Other holdings (3): bonds, preferreds, convertibles and warrants · $3.2M (not counted above)
SecurityClassShares / PrincipalValueChange
NUVB.WS Nuvation Bio Inc. -CW27 *W EXP 02/10/202 963,333$2.2MNo change
SRZNW Surrozen Inc.-CW25 *W EXP 08/01/203 66,665$799KNo change
CMXWQ Caremax-CW *W EXP 06/08/202 100,000$170KNo change

Total filed on the 13F, all lines: $2.9B.

Portfolio Sells Q2 2024 → Q3 2024
SRPT Sarepta Therapeutics Inc. Sold out 0.00% −6.81
MORF Morphic Holding Inc. Sold out 0.00% −5.20
LKFT Lakefront Biotherapeutic-ADR Reduce -97.3% 0.15% −4.22
ITOS Iteos Therapeutics Inc. Reduce -50.5% 0.56% −0.91
ACAD Acadia Pharmaceuticals Inc. Sold out 0.00% −0.67
LENZ Lenz Therapeutics Inc. Reduce -71.6% 0.28% −0.36
RCKT Rocket Pharmaceuticals Inc. Sold out 0.00% −0.34
PRQR Proqr Therapeutics NV Reduce -10.1% 0.11% +0.01
CNTA Centessa Pharmaceuticals Ltd. Reduce -43.6% 1.77% +0.19

Portfolio Buys Q2 2024 → Q3 2024
JAZZ Jazz Pharmaceuticals PLC Add +68.3% 6.52% +3.20
ANAB Anaptysbio Inc. Add +3.6% 8.95% +3.18
CRNX Crinetics Pharmaceuticals Inc. Add +3.2% 7.51% +1.81
VRDN Viridian Therapeutics Inc. New 1.53% +1.53
MBX MBX Biosciences Inc. New 1.05% +1.05
PCVX Vaxcyte Inc. Add +17.5% 1.38% +0.69
IONS Ionis Pharmaceuticals Inc. New 0.69% +0.69
RLAY Relay Therapeutics Inc. New 0.61% +0.61
DAWN Day One Biopharmaceuticals I New 0.41% +0.41
DYN Dyne Therapeutics Inc. Add +30.1% 0.68% +0.22
BBIO Bridgebio Pharma Inc. New 0.15% +0.15
WHWK Whitehawk Therapeutics Inc. New 0.13% +0.13
ETON Eton Pharmaceuticals Inc. New 0.12% +0.12
ATRA Atara Biotherapeutics Inc. Add +15.3% 0.13% +0.02
ARTV Artiva Biotherapeutics Inc. New 0.02% +0.02
DSGN Design Therapeutics Inc. New 0.01% +0.01
MGNX Macrogenics Inc. New 0.01% +0.01
ALLK Allakos LLC New 0.00% +0.00
APLS Apellis Pharmaceuticals Inc. Add +2.4% 11.76% −1.88

Options Activity Q2 2024 → Q3 2024
ETON Eton Pharmaceuticals Inc. call New 228,000 $1.4M

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