Assembly Biosciences, Inc. (ASMB) Institutional Ownership

Ownership Summary

A total of 57 institutions have reported a stake in Assembly Biosciences, Inc. (NASDAQ:ASMB) as of September 2025, according to recent 13F filings with the SEC.

• Institutional ownership in Assembly Biosciences edged up to 167.1% in September 2025, compared to 40.8% in June 2025.
• On a quarter-over-quarter basis, institutional holdings shifted by 302.61%, with a year-over-year an increase of 90.00% in the count of filers.
• During the quarter, 44 institutions bought more Assembly Biosciences shares, 5 sold shares, and 8 of the 57 total investors held their position steady.
• The aggregate institutional position in Assembly Biosciences now stands at 12.82Mn shares as of September 2025, after investors increased their holdings (up by 9.64Mn shares quarter on quarter which is up 11.79Mn shares year over year).
• With 4.51Mn shares, GILEAD SCIENCES, INC. commands the largest institutional position in Assembly Biosciences as of September 30, 2025, equating to 58.72% of the company.
• Among the most significant buyers of Assembly Biosciences during September 2025 were GILEAD SCIENCES, INC. (2.30Mn), FARALLON CAPITAL MANAGEMENT LLC (1.23Mn), RA CAPITAL MANAGEMENT, L.P. (1.02Mn), Commodore Capital LP (1.00Mn), JANUS HENDERSON GROUP PLC (752.63K).
• Leading sellers of Assembly Biosciences stock in September 2025 included MILLENNIUM MANAGEMENT LLC (15.95K), B Group, Inc. (13.64K), GSA CAPITAL PARTNERS LLP (2.42K), BNP PARIBAS FINANCIAL MARKETS (244), OSAIC HOLDINGS, INC. (87).
• The top 10 institutional holders of Assembly Biosciences for the quarter ending September 2025 included GILEAD SCIENCES, INC. (4.51Mn), FARALLON CAPITAL MANAGEMENT LLC (1.23Mn), RA CAPITAL MANAGEMENT, L.P. (1.02Mn), Commodore Capital LP (1.00Mn), JANUS HENDERSON GROUP PLC (752.63K), VANGUARD GROUP INC (502.11K), Frazier Life Sciences Management, L.P. (456.25K), Blackstone Inc. (447.79K), Caption Management, LLC (349.80K), Point72 Asset Management, L.P. (296.02K).