EcoR1 Capital, LLC

13F Portfolio Filings

Most recent 13F
Q2 2026
13D/G filings
13D on 5 securities, 13G on 30 securities
Location
San Francisco, CA
CIK
0001587114
All SEC filings
View on sec.gov
Holdings Value
Quarter Holdings Value ($000) Top Holdings Form Type Date Filed Filing ID
Q2 2026 33 2,056,733 ZYME, ANAB, AKTS, CGON 13F-HR 8/14/2026 000093583626000415
Q1 2026 30 2,356,318 ZYME, ANAB, JAZZ, CNTA 13F-HR 5/15/2026 000093583626000270
Q4 2025 30 2,204,008 ZYME, ANAB, JAZZ, CRNX 13F-HR 2/17/2026 000093583626000101
Q3 2025 30 2,083,868 ZYME, ANAB, QURE, JAZZ 13F-HR 11/14/2025 000093583625000671
Q2 2025 37 1,689,330 ZYME, APLS, JAZZ, ANAB 13F-HR 8/14/2025 000093583625000506
Q1 2025 46 1,686,022 APLS, JAZZ, ZYME, ANAB 13F-HR 5/15/2025 000093583625000338
Q4 2024 59 2,645,070 APLS, ZYME, CRNX, JAZZ 13F-HR 2/14/2025 000093583625000164
Q3 2024 64 2,921,575 APLS, ANAB, CRNX, PRTA 13F-HR 11/14/2024 000093583624000682
Q2 2024 55 3,268,881 APLS, PRTA, SRPT, ANAB 13F-HR 8/14/2024 000093583624000519
Q1 2024 59 3,953,710 APLS, PRTA, ARVN, SRPT 13F-HR 5/15/2024 000093583624000391
Q4 2023 51 3,851,537 APLS, MRTX, PRTA, ARVN 13F-HR 2/14/2024 000093583624000163
Q3 2023 51 2,964,695 PRTA, APLS, MRTX, LKFT 13F-HR 11/14/2023 000093583623000696
Q2 2023 53 4,081,490 PRTA, APLS, SRPT, JNJ calls 13F-HR 8/14/2023 000093583623000570
Q1 2023 58 3,105,401 PRTA, SRPT, APLS, LKFT 13F-HR 5/15/2023 000093583623000412
Q4 2022 66 3,285,596 PRTA, SRPT, APLS, ANAB 13F-HR 2/14/2023 000093583623000229
Q3 2022 76 3,388,131 PRTA, APLS, SRPT, ANAB 13F-HR 11/14/2022 000156761922019766
Q2 2022 80 2,897,047 PRTA, APLS, SRPT, SGEN 13F-HR 8/15/2022 000156761922016025
Q1 2022 87 3,196,837 PRTA, APLS, LKFT, ANAB 13F-HR 5/16/2022 000156761922010677
Q4 2021 76 3,138,062 PRTA, ANAB, RCUS, XNCR 13F-HR 2/14/2022 000156761922003866
Q3 2021 71 2,874,475 PRTA, MORF, ANAB, RCUS RESTATEMENT 11/22/2021 000156761921020941
Q2 2021 72 2,675,754 PRTA, MORF, ANAB, XNCR 13F-HR 8/16/2021 000156761921015658
Q1 2021 71 2,254,663 PRTA, XNCR, MORF, ANAB 13F-HR 5/17/2021 000156761921010348
Q4 2020 66 1,860,183 XNCR, RLAY, STTK, SPRY 13F-HR 2/16/2021 000156761921003800
Q3 2020 50 1,402,501 XNCR, KURA, RLAY, PRTA 13F-HR 11/16/2020 000156761920019716
Q2 2020 49 1,354,085 XNCR, PRTA, ORIC, MORF 13F-HR 8/14/2020 000156761920015276
Q1 2020 51 957,232 PRTA, XNCR, ARVN, DRNA 13F-HR 5/15/2020 000156761920010491
Q4 2019 44 1,109,471 PRTA, XNCR, DRNA, FGEN RESTATEMENT 2/18/2020 000156761920004215
Q3 2019 38 791,886 XNCR, PRTA, ONCE, KURA 13F-HR 11/14/2019 000156761919021573
Q2 2019 39 989,642 KURA, XNCR, ARGX, CRSP 13F-HR 8/14/2019 000156761919017041
Q1 2019 41 1,084,777 ARGX, KURA, MRTX, CRSP 13F-HR 5/15/2019 000156761919011227
Q4 2018 53 999,389 ARGX, KURA, FGEN, IRWD 13F-HR 2/14/2019 000156761919004400
Q3 2018 50 1,110,045 FGEN, ASMB, IRWD, ASND 13F-HR 11/14/2018 000156761918006356
Q2 2018 33 1,050,372 FGEN, IRWD, ASMB, ASND 13F-HR 8/14/2018 000156761918000858
Q1 2018 31 997,012 ASMB, ASND, FGEN, IRWD 13F-HR 5/15/2018 000114036118023901
Q4 2017 30 888,086 ASMB, FGEN, CELGENE CORPORATION calls, IRWD 13F-HR 2/14/2018 000114036118007942
Q3 2017 39 750,316 ASMB, FGEN, IRWD, ASND 13F-HR 11/14/2017 000114036117042799
Q2 2017 36 563,229 ALEXION PHARMACEUTICALS, INC calls, IRWD, ASMB, FGEN 13F-HR 8/14/2017 000114036117032004
Q1 2017 33 395,567 ASMB, IRWD, LKFT, GILEAD SCIENCES INC calls RESTATEMENT 5/19/2017 000114036117021481
Q4 2016 30 299,427 IRWD, LKFT, ASMB, ALXN RESTATEMENT 2/15/2017 000114036117007745
Q4 2016 1 14,684 FGEN NEW HOLDINGS 2/15/2017 000114036117007752
Q3 2016 31 325,892 IRWD, LKFT, BRISTOL MYERS SQUIBB CO calls, ASMB 13F-HR 11/14/2016 000114036116086430
Q2 2016 32 253,622 IRWD, LKFT, RTRX, CYTK 13F-HR 8/15/2016 000114036116076455
Q1 2016 37 286,194 IRWD, FPRX, EPZM, FGEN 13F-HR 5/16/2016 000114036116065705
Q4 2015 31 318,400 FGEN, FPRX, JAZZ PHARMACEUTICALS calls, RTRX 13F-HR 2/16/2016 000114036116052684
Q3 2015 25 219,698 FGEN, ATRA, ARRAY BIOPHARMA INC, RTRX 13F-HR 11/16/2015 000114036115041435
Q2 2015 25 299,936 ATRA, EPZM, ASMB, FGEN 13F-HR 8/14/2015 000114036115031882
Q1 2015 23 300,071 ATRA, EPZM, RCPT, ARRAY BIOPHARMA SR CONV NT 3.000% Due 06/01/2020 RESTATEMENT 5/18/2015 000114036115020512
Q4 2014 22 197,602 KITE, CLVSQ, RCPT, ARRAY BIOPHARMA INC 13F-HR 2/17/2015 000092189515000435
Additional filings from EcoR1 Capital, LLC that have since been restated

13D and 13G Filings

All 13D and 13G filings

Investors who own more than 5% of a class must file a Schedule 13D or 13G. Each security where the latest filing since 12/18/2024 is a 13D, newest first.

Issuer % of Class Filed
Aktis Oncology, Inc. 13D
AKTS · 01021M104
 9.1% 1/20/2026
Event 1/12/2026
Zymeworks Inc. 13D/A
ZYME · 98985Y108
 30.7% 11/19/2025
Event 11/16/2025
Galapagos NV 13D/A
LKFT · 36315X101
 13.2% 7/28/2025
Event 7/24/2025
iTeos Therapeutics, Inc. 13D
ITOS · 46565G104
 27.9% 5/16/2025
Event 5/15/2025
Under 5%, checked the "5 percent or less" box, or amended by a later filing (1)
Prothena Corp Public Ltd Co 13D/A
PRTA · G72800108
 0% 5/29/2025
Event 5/27/2025

30 other securities where the latest filing is a 13G, the newest filed 8/14/2026. View all