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EcoR1 Capital, LLC

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13F filer, CIK 1587114, San Francisco, CA

EcoR1 Capital, LLC reported $2,083,868,932 across 30 holdings for the quarter ended 2025-09-30, in a 13F-HR filed 2025-11-14. Its ten largest share positions make up 80.63% of the portfolio.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0000935836-25-000671

Period
2025-09-30
Reported value
$2.08B
Holdings
30
Top 10 weight
80.63%
New
6
Sold out
13

Largest buys vs the previous quarter

SecurityShares changeApprox. value
ORICadded+5,110,048$61.3M
BBOTnew+2,823,126$32.7M
LKFTadded+630,174$21.8M
MBXadded+973,810$17M
AQSTnew+2,625,000$14.7M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Largest sells vs the previous quarter

SecurityShares changeApprox. value
APLSreduced-8,448,652-$191M
ITEOS THERAPEUTICS INCexited-10,688,978-$107M
JANXexited-1,469,818-$34M
KURAreduced-3,327,500-$29.4M
AKROexited-440,000-$23.5M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Holdings, Q3 2025

Share positions as resolved from 13F-HR 0000935836-25-000671, largest first. % of portfolio is the value over $2,083,868,932, the sum of the share positions whose value is usable for ratios (method).

SecurityHistorySharesValue% of portfolioChangeLatest eventTimeline
ZYMEZYMEWORKS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 13,437,473 shares; 2024Q4: 15,028,079 shares; 2025Q1: 17,259,548 shares; 2025Q2: 22,970,388 shares; 2025Q3: 22,970,388 shares 22,970,388$392M18.83%0Timeline
ANABANAPTYSBIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 7,794,996 shares; 2024Q4: 7,873,448 shares; 2025Q1: 7,880,094 shares; 2025Q2: 7,880,094 shares; 2025Q3: 7,880,094 shares 7,880,094$241M11.58%0Timeline
QUREUNIQURE NVQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: 3,400,000 shares; 2025Q1: 3,988,971 shares; 2025Q2: 3,988,971 shares; 2025Q3: 3,988,971 shares 3,988,971$233M11.17%0Timeline
JAZZJAZZ PHARMACEUTICALS PLCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 1,706,469 shares; 2024Q4: 1,706,469 shares; 2025Q1: 1,706,469 shares; 2025Q2: 1,706,469 shares; 2025Q3: 1,706,469 shares 1,706,469$225M10.79%0Timeline
CRNXCRINETICS PHARMACEUTICALS INQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 4,288,120 shares; 2024Q4: 4,288,120 shares; 2025Q1: 4,288,120 shares; 2025Q2: 4,288,120 shares; 2025Q3: 4,288,120 shares 4,288,120$179M8.57%0Timeline
CRSPCRISPR THERAPEUTICS AGQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 1,389,276 shares; 2024Q4: 1,389,276 shares; 2025Q1: 1,389,276 shares; 2025Q2: 1,389,276 shares; 2025Q3: 1,389,276 shares 1,389,276$90M4.32%0Timeline
TNGXTANGO THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 13,330,736 shares; 2024Q4: 10,630,736 shares; 2025Q1: 10,630,736 shares; 2025Q2: 10,630,736 shares; 2025Q3: 10,630,736 shares 10,630,736$89.3M4.29%0Timeline
ORICORIC PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,418,068 shares; 2024Q4: 3,418,068 shares; 2025Q1: 3,418,068 shares; 2025Q2: 1,618,068 shares; 2025Q3: 6,728,116 shares 6,728,116$80.7M3.87%+5,110,048Timeline
APLSAPELLIS PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 11,890,843 shares; 2024Q4: 11,890,843 shares; 2025Q1: 11,895,808 shares; 2025Q2: 11,895,808 shares; 2025Q3: 3,447,156 shares 3,447,156$78M3.74%-8,448,652Timeline
XNCRXENCOR INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 5,330,416 shares; 2024Q4: 6,144,767 shares; 2025Q1: 6,144,767 shares; 2025Q2: 6,144,767 shares; 2025Q3: 6,144,767 shares 6,144,767$72.1M3.46%0Timeline
LKFTLAKEFRONT BIOTHERAPEUTICS NVQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 155,006 shares; 2024Q4: 155,006 shares; 2025Q1: 155,006 shares; 2025Q2: 1,036,945 shares; 2025Q3: 1,667,119 shares 1,667,119$57.7M2.77%+630,174Timeline
IMNMIMMUNOME INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,879,415 shares; 2024Q4: 3,879,415 shares; 2025Q1: 4,079,415 shares; 2025Q2: 4,079,415 shares; 2025Q3: 4,079,415 shares 4,079,415$47.8M2.29%0Timeline
ETONETON PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 566,075 shares; 2024Q4: 1,829,603 shares; 2025Q1: 1,939,288 shares; 2025Q2: 2,030,544 shares; 2025Q3: 2,030,544 shares 2,030,544$44.1M2.12%0Timeline
MBXMBX BIOSCIENCES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 1,175,809 shares; 2024Q4: 1,259,273 shares; 2025Q1: 1,259,273 shares; 2025Q2: 1,149,794 shares; 2025Q3: 2,123,604 shares 2,123,604$37.2M1.78%+973,810Timeline
MDGLMADRIGAL PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 75,000 shares; 2024Q4: 75,000 shares; 2025Q1: 75,000 shares; 2025Q2: 75,000 shares; 2025Q3: 75,000 shares 75,000$34.4M1.65%0Timeline
RNAMAVIDITY BIOSCIENCES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 757,576 shares; 2024Q4: 557,576 shares; 2025Q1: 557,576 shares; 2025Q2: 500,000 shares; 2025Q3: 765,000 shares 765,000$33.3M1.6%+265,000Timeline
BBOTBRIDGEBIO ONCOLOGY THERAPEUTQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 2,823,126 shares 2,823,126$32.7M1.57%newTimeline
NGNENEUROGENE INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 1,271,342 shares; 2024Q4: 1,271,342 shares; 2025Q1: 1,271,342 shares; 2025Q2: 1,271,342 shares; 2025Q3: 1,271,342 shares 1,271,342$22M1.06%0Timeline
ALKSALKERMES PLCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: 500,000 shares; 2025Q3: 500,000 shares 500,000$15M0.72%0Timeline
AQSTAQUESTIVE THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 2,625,000 shares 2,625,000$14.7M0.7%newTimeline
MTSRMETSERA INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: 50,000 shares; 2025Q2: 271,529 shares; 2025Q3: 271,529 shares 271,529$14.2M0.68%0Timeline
CNTACENTESSA PHARMACEUTICALS PLCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,223,851 shares; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 550,000 shares 550,000$13.3M0.64%newTimeline
PRMEPRIME MEDICINE INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 700,000 shares; 2024Q4: 700,000 shares; 2025Q1: 700,000 shares; 2025Q2: not reported; 2025Q3: 1,543,326 shares 1,543,326$8.55M0.41%newTimeline
ATRAATARA BIOTHERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 468,938 shares; 2024Q4: 532,134 shares; 2025Q1: 573,183 shares; 2025Q2: 573,183 shares; 2025Q3: 573,183 shares 573,183$8.21M0.39%0Timeline
KURAKURA ONCOLOGY INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 5,806,871 shares; 2024Q4: 3,557,269 shares; 2025Q1: 2,640,298 shares; 2025Q2: 4,200,000 shares; 2025Q3: 872,500 shares 872,500$7.72M0.37%-3,327,500Timeline
PEPGPEPGEN INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 800,000 shares 800,000$3.7M0.18%newTimeline
NUVATION BIO INCNUVATION BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 963,333 shares; 2024Q4: 963,333 shares; 2025Q1: 963,333 shares; 2025Q2: 963,333 shares; 2025Q3: 963,333 shares 963,333$3.56M0.17%0
VYGRVOYAGER THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,917,546 shares; 2024Q4: 3,917,546 shares; 2025Q1: 3,917,546 shares; 2025Q2: 3,917,546 shares; 2025Q3: 670,303 shares 670,303$3.13M0.15%-3,247,243Timeline
CMPSCOMPASS PATHWAYS PLCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 265,137 shares 265,137$1.52M0.07%newTimeline
SRZNWSURROZEN INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 66,665 shares; 2024Q4: 66,665 shares; 2025Q1: 66,665 shares; 2025Q2: 66,665 shares; 2025Q3: 66,665 shares 66,665$859K0.04%0Timeline

Sold out in Q3 2025

Positions in the previous quarter's report that this quarter's report no longer lists.

SecurityShares beforeValue beforeType
ITEOS THERAPEUTICS INCITEOS THERAPEUTICS INC10,688,978$107Mshares
JANXJANUX THERAPEUTICS INC1,469,818$34Mshares
AKROAKERO THERAPEUTICS INC440,000$23.5Mshares
VERONA PHARMA PLCVERONA PHARMA PLC200,000$18.9Mshares
TECXTECTONIC THERAPEUTIC INC935,121$18.6Mshares
PCRXPACIRA BIOSCIENCES INC457,471$10.9Mshares
REPLREPLIMUNE GROUP INC850,341$7.9Mshares
ADAPYADAPTIMMUNE THERAPEUTICS PLC S27,404,070$6.57Mshares
DAWNDAY ONE BIOPHARMACEUTICALS I862,068$5.6Mshares
HILLEVAX INCHILLEVAX INC2,420,243$4.82Mshares
WHWKWHITEHAWK THERAPEUTICS INC1,091,417$2.04Mshares
MGNXMACROGENICS INC1,602,717$1.94Mshares
QUREUNIQURE NV135,000$1.88Mcall

How Q3 2025 was built

Available 13F filings of this filer for the quarter and their roles: the base report is the latest original or restatement, NEW HOLDINGS amendments filed after it are added (method).

FilingRoleAmendmentFiledAcceptedIngested
13F-HR 0000935836-25-000671 base2025-11-14acceptance time not in the bulk data set