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Assembly Biosciences, Inc.

ASMB
Exchange
Nasdaq
Industry
Pharmaceutical Preparations
SEC CIK
0001426800

No open-market purchases or sales by Assembly Biosciences, Inc. insiders were filed in the last 90 days; 92 institutions reported holding it in 13F filings for Q2 2026, worth $514.8M in total; no superinvestor holds it.

Holders of 5% or more of ASMB

Holders whose latest Schedule 13D or 13G filing reports 5% or more of Assembly Biosciences, Inc., largest stake first. The change is against the holder's previous filing.

Holders of 5% or more of ASMB
HolderLatest formStakeChangeFirst filedLatest filingFiling
Gilead Sciences, Inc.13D/A25.10%4.98M shares−3.90 ppfrom 29.00%Oct 25, 20235 filingsMay 27, 2026SEC
Commodore Capital LP13G9.90%1.62M sharesNewAug 15, 20251 filingAug 15, 2025SEC
Ra Capital Management, L.P.13G9.50%1.53M sharesNewAug 18, 20251 filingAug 18, 2025SEC
Farallon Capital Management, L.L.C.13G/A8.10%1.60M shares–Aug 4, 20261 filingAug 4, 2026SEC
Paradigm Biocapital Advisors LP13G/A7.80%1.55M shares+2.40 ppfrom 5.40%May 11, 20262 filingsAug 14, 2026SEC
Farallon Capital Partners, L.P.13G/A7.80%1.23M shares+0.50 ppfrom 7.30%Aug 15, 20252 filingsFeb 9, 2026SEC
Janus Henderson Group PLC13G/A6.90%1.36M shares−1.30 ppfrom 8.20%Dec 8, 20252 filingsAug 13, 2026SEC

Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.

13D and 13G filings

42 Schedule 13D and 13G filings on Assembly Biosciences, Inc., newest first, including old-format filings without a stake.

Schedule 13D and 13G filings on ASMB
Filed (ET)FilerFormStakeChangeEvent dateFiling
Aug 14, 20264:23 PM ETParadigm Biocapital Advisors LPand 3 others13G/A7.80%1.55M shares+2.40 ppfrom 5.40%Jun 30, 2026SEC
Aug 13, 202612:47 PM ETJanus Henderson Group PLC13G/A6.90%1.36M shares−1.30 ppfrom 8.20%Jun 30, 2026SEC
Aug 4, 20268:29 AM ETFarallon Capital Management, L.L.C.and 26 others13G/A8.10%1.60M shares–Jun 30, 2026SEC
May 27, 20268:51 PM ETGilead Sciences, Inc.13D/A25.10%4.98M shares−3.90 ppfrom 29.00%May 22, 2026SEC
May 11, 20264:02 PM ETParadigm Biocapital Advisors LPand 3 others13G5.40%865.3K sharesNewMay 4, 2026SEC
Feb 9, 20268:46 AM ETFarallon Capital Partners, L.P.and 28 others13G/A7.80%1.23M shares+0.50 ppfrom 7.30%Dec 31, 2025SEC
Dec 8, 202511:43 AM ETJanus Henderson Group PLC13G8.20%1.34M sharesNewNov 28, 2025SEC
Aug 18, 20255:52 PM ETRa Capital Management, L.P.and 3 others13G9.50%1.53M sharesNewAug 11, 2025SEC
Aug 18, 20254:18 PM ETSchornstein Alexander13G/A3.49%543.5K shares−1.19 ppfrom 4.68%Below 5%Aug 11, 2025SEC
Aug 15, 20256:56 PM ETFarallon Capital Partners, L.P.and 27 others13G7.30%1.14M sharesNewAug 8, 2025SEC
Aug 15, 20254:01 PM ETCommodore Capital LPand 3 others13G9.90%1.62M sharesNewAug 8, 2025SEC
Aug 12, 20255:29 PM ETSchornstein Alexander13G4.68%728.1K shares−5.31 ppfrom 9.99%Below 5%Aug 11, 2025SEC
Aug 12, 20254:30 PM ETGilead Sciences, Inc.13D/A29.00%4.51M shares−0.90 ppfrom 29.90%Aug 8, 2025SEC
Feb 14, 20254:58 PM ETArmistice Capital, LLCand 1 other13G/A4.99%316.1K shares–Below 5%Dec 31, 2024SEC
Dec 23, 20248:17 PM ETGilead Sciences, Inc.13D/A29.90%2.21M shares–Dec 19, 2024SEC
Dec 23, 20245:34 PM ETSchornstein Alexander13G/A9.99%728.1K shares0.00 ppfrom 9.99%Dec 19, 2024SEC
Dec 23, 202411:59 AM ETSchornstein Alexander13G9.99%728.1K shares–Jun 24, 2024SEC
Nov 14, 2024Armistice Capital, LLC13GOld format–––SEC
Jun 24, 2024Schornstein Alexander13D/AOld format–––SEC
Jun 20, 2024Gilead Sciences, Inc.13D/AOld format–––SEC
Nov 22, 2023Schornstein Alexander13D/AOld format–––SEC
Nov 3, 2023Schornstein Alexander13D/AOld format–––SEC
Oct 31, 2023Schornstein Alexander13DOld format–New–SEC
Oct 25, 2023Gilead Sciences, Inc.13DOld format–New–SEC
Feb 14, 2023Deep Track Capital, LP13G/AOld format–––SEC
Feb 15, 2022Armistice Capital, LLC13G/AOld format–––SEC
Feb 14, 2022Deep Track Capital, LP13G/AOld format–––SEC
Feb 14, 2022Consonance Capital Management LP13G/AOld format–––SEC
Feb 10, 2022Satter Muneer A13G/AOld format–––SEC
Feb 9, 2022Vanguard Group Inc13G/AOld format–––SEC
Oct 12, 2021Deep Track Capital, LP13GOld format–New–SEC
Jul 12, 20218:29 AM ETBlackRock Inc.13G/AOld format–––SEC
Feb 17, 2021Consonance Capital Management LP13GOld format–––SEC
Feb 16, 2021Consonance Capital Management LP13GOld format–––SEC
Feb 16, 2021Consonance Capital Management LP13GOld format–New–SEC
Feb 16, 2021Armistice Capital, LLC13GOld format–New–SEC
Feb 12, 2021Satter Muneer A13G/AOld format–––SEC
Feb 10, 2021Vanguard Group Inc13GOld format–New–SEC
Feb 10, 2021Jennison Associates LLC13G/AOld format–––SEC
Feb 9, 2021Prudential Financial Inc13G/AOld format–––SEC
Jan 28, 20215:55 PM ETBlackRock Inc.13G/AOld format–––SEC
Jan 4, 2021Satter Muneer A13GOld format–New–SEC

Form 144: proposed insider sales

4 notices from officers, directors and other affiliates planning to sell Assembly Biosciences, Inc. shares, newest first.

Form 144 notices for ASMB
Filed (ET)SellerShares to sellMarket valuePlanned saleBrokerFiling
May 30, 20235:48 PM ETWilliam E. Delaney IVOfficer4.23K$4.05KMay 30, 2023Morgan Stanley Smith Barney LLCSEC
May 23, 20236:35 PM ETWilliam E. Delaney IVOfficer6.56K$6.83KMay 23, 2023Morgan Stanley Smith Barney LLCSEC
May 23, 20236:33 PM ETJason OkazakiOfficer · Director6.56K$6.83KMay 23, 2023Morgan Stanley Smith Barney LLCSEC
May 23, 20236:30 PM ETJohn G. McHutchisonDirector26.0K$27.0KMay 23, 2023Morgan Stanley Smith Barney LLCSEC