EcoR1 Capital, LLC

In its 13F for Q2 2024 (holdings as of June 30, 2024, filed August 14, 2024), EcoR1 Capital, LLC reported 52 stock positions worth $3.3 billion. Its top holding was Apellis Pharmaceuticals (APLS) at 13.6% of the portfolio, followed by Prothena (PRTA, 7.3%) and Sarepta Therapeutics (SRPT, 6.8%). Compared with Q1 2024, it opened 7 new positions, sold out of 9, added to 5 and reduced 4. The biggest buy was Morphic (MORF, shares +109%) and the biggest sale Acadia Pharmaceuticals (ACAD, shares −78%).

Most Recent 13F
Q2 2026
Location
San Francisco, CA
CIK
0001587114
Portfolio Value
$3.3B (Q2 2024)
SEC Filing
0000935836-24-000519 ↗ filed Aug 14, 2024

Holdings Value

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

Holdings 52 stocks · $3.3B
APLS Apellis Pharmaceuticals Inc. 13.64% 11,607,425 $445.3M Add +2.2%
PRTA Prothena Corp. PLC 7.32% 11,584,280 $239.1M No change
SRPT Sarepta Therapeutics Inc. 6.81% 1,407,322 $222.4M Reduce -26.7%
ANAB Anaptysbio Inc. 5.77% 7,521,024 $188.5M No change
CRNX Crinetics Pharmaceuticals Inc. 5.70% 4,155,375 $186.1M No change
ARVN Arvinas Inc. 5.48% 6,726,491 $179.1M No change
MORF Morphic Holding Inc. 5.20% 4,982,945 $169.8M Add +109.0%
LKFT Lakefront Biotherapeutic-ADR filed as GALAPAGOS NV 4.37% 5,756,268 $142.6M No change
KURA Kura Oncology Inc. 3.66% 5,806,871 $119.6M No change
TNGX Tango Therapeutics Inc. 3.50% 13,330,736 $114.4M No change
ZYME Zymeworks Inc. 3.50% 13,437,473 $114.4M No change
JAZZ Jazz Pharmaceuticals PLC 3.31% 1,013,952 $108.2M No change
XNCR Xencor Inc. 3.09% 5,330,416 $100.9M No change
CRSP Crispr Therapeutics AG 2.30% 1,389,276 $75.0M No change
JANX Janux Therapeutics Inc. 1.89% 1,469,818 $61.6M New
NUVB Nuvation Bio Inc. 1.72% 19,209,643 $56.1M No change
CNTA Centessa Pharmaceuticals Ltd. 1.58% 5,714,404 $51.6M Add +1.7%
ITOS Iteos Therapeutics Inc. 1.48% 3,249,835 $48.2M Add +62.5%
IMNM Immunome Inc. 1.44% 3,879,415 $46.9M No change
NGNE Neurogene Inc. 1.42% 1,271,342 $46.3M No change
THRD Third Harmonic Bio Inc. 1.27% 3,182,444 $41.4M No change
MERSANA THERAPEUTICS INC 1.19% 19,364,688 $38.9M No change
VYGR Voyager Therapeutics Inc. 0.95% 3,917,546 $31.0M No change
RNAM Avidity Biosciences Inc. 0.95% 757,576 $30.9M No change
TCRX Tscan Therapeutics Inc. 0.90% 5,000,000 $29.3M No change
ADAPY Adaptimmune Therapeutics-ADR 0.82% 27,404,070 $26.7M No change
ORIC Oric Pharmaceuticals Inc. 0.74% 3,418,068 $24.2M No change
CRGX Cargo Therapeutics Inc. 0.74% 1,470,000 $24.1M New
CLDX Celldex Therapeutics Inc. 0.74% 650,000 $24.1M No change
PCVX Vaxcyte Inc. 0.69% 300,000 $22.7M No change
EWTX Edgewise Therapeutics Inc. 0.69% 1,250,385 $22.5M No change
ACAD Acadia Pharmaceuticals Inc. 0.67% 1,346,475 $21.9M Reduce -77.5%
LENZ Lenz Therapeutics Inc. 0.65% 1,219,774 $21.1M No change
MDGL Madrigal Pharmaceuticals Inc. 0.64% 75,000 $21.0M No change
NMRA Neumora Therapeutics Inc. 0.62% 2,071,450 $20.4M No change
BCYC Bicycle Therapeutics PLC-ADR 0.56% 910,000 $18.4M New
AVIR Atea Pharmaceuticals Inc. 0.55% 5,441,896 $18.0M Reduce -11.4%
PHVS Pharvaris NV 0.52% 900,000 $16.9M No change
DYN Dyne Therapeutics Inc. 0.46% 427,039 $15.1M No change
TECX Tectonic Therapeutic Inc. 0.43% 849,143 $14.0M New
RCKT Rocket Pharmaceuticals Inc. 0.34% 508,393 $10.9M New
KROS Keros Therapeutics Inc. 0.26% 187,500 $8.6M No change
ALLOVIR INC 0.25% 11,294,585 $8.2M No change
REPL Replimune Group Inc. 0.23% 850,341 $7.7M New
VERV Verve Therapeutics Inc. 0.19% 1,250,000 $6.1M No change
GBIO Generation Bio Co. 0.18% 2,046,867 $5.8M No change
PRME Prime Medicine Inc. 0.11% 700,000 $3.6M No change
ATRA Atara Biotherapeutics Inc. 0.11% 406,679 $3.5M New
PRQR Proqr Therapeutics NV 0.10% 2,042,771 $3.4M Reduce -29.2%
HOOKIPA PHARMA INC 0.10% 5,717,324 $3.4M Add +24.4%
KYTX Kyverna Therapeutics Inc. 0.10% 450,000 $3.4M No change
ALGS Aligos Therapeutics Inc. 0.07% 6,389,468 $2.2M No change
Other holdings (3): bonds, preferreds, convertibles and warrants · $3.8M (not counted above)
SecurityClassShares / PrincipalValueChange
NUVB.WS Nuvation Bio Inc. -CW27 *W EXP 02/10/202 963,333$2.8MNo change
SRZNW Surrozen Inc.-CW25 *W EXP 08/01/203 66,665$730KNo change
CMXWQ Caremax-CW *W EXP 06/08/202 100,000$279KNo change

Total filed on the 13F, all lines: $3.3B.

Portfolio Sells Q1 2024 → Q2 2024
ACAD Acadia Pharmaceuticals Inc. Reduce -77.5% 0.67% −2.15
ALEC Alector Inc. Sold out 0.00% −0.62
NKTX Nkarta Inc. Sold out 0.00% −0.55
OVID Ovid Therapeutics Inc. Sold out 0.00% −0.47
GOSS Gossamer Bio Inc. Sold out 0.00% −0.28
KOD Kodiak Sciences Inc. Sold out 0.00% −0.22
ATRA Atara Biotherapeutics Inc. Sold out 0.00% −0.18
ARQT Arcutis Biotherapeutics Inc. Sold out 0.00% −0.13
AVIR Atea Pharmaceuticals Inc. Reduce -11.4% 0.55% −0.08
PRQR Proqr Therapeutics NV Reduce -29.2% 0.10% −0.06
PMVP PMV Pharmaceuticals Inc. Sold out 0.00% −0.02
ALPN Alpine Immune Sciences Inc. Sold out 0.00% −0.00
SRPT Sarepta Therapeutics Inc. Reduce -26.7% 6.81% +0.49

Portfolio Buys Q1 2024 → Q2 2024
MORF Morphic Holding Inc. Add +109.0% 5.20% +3.07
JANX Janux Therapeutics Inc. New 1.89% +1.89
ITOS Iteos Therapeutics Inc. Add +62.5% 1.48% +0.78
CRGX Cargo Therapeutics Inc. New 0.74% +0.74
BCYC Bicycle Therapeutics PLC-ADR New 0.56% +0.56
TECX Tectonic Therapeutic Inc. New 0.43% +0.43
RCKT Rocket Pharmaceuticals Inc. New 0.34% +0.34
REPL Replimune Group Inc. New 0.23% +0.23
ATRA Atara Biotherapeutics Inc. New 0.11% +0.11
HOOKIPA PHARMA INC Add +24.4% 0.10% +0.02
CNTA Centessa Pharmaceuticals Ltd. Add +1.7% 1.58% −0.03
APLS Apellis Pharmaceuticals Inc. Add +2.2% 13.64% −3.33

Options Activity Q1 2024 → Q2 2024
KURA Kura Oncology Inc. call Sold out 700,000 $14.9Mbefore exit
KOD Kodiak Sciences Inc. call Sold out 51,100 $269Kbefore 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