Amylyx Pharmaceuticals, Inc. (AMLX) Institutional Ownership

Ownership Summary

Recent 13F filings as of September 2025 show that 168 institutional investors hold a position in Amylyx Pharmaceuticals, Inc. (NASDAQ:AMLX).

• Amylyx Pharmaceuticals saw its institutional ownership percentage rose to 125.5% in September 2025 from 90.0% in June 2025.
• On a quarter-over-quarter basis, institutional holdings shifted by 31.44%, with a year-over-year an increase of 55.56% in the count of filers.
• The latest 13F cycle for Amylyx Pharmaceuticals reveals that of 168 total investors, 88 funds grew their exposure, whereas 63 reduced theirs and 17 made no changes.
• The aggregate institutional position in Amylyx Pharmaceuticals now stands at 111.90Mn shares as of September 2025, after investors increased their holdings (up by 26.77Mn shares quarter on quarter which is up 68.84Mn shares year over year).
• As of September 30, 2025, FMR LLC held Amylyx Pharmaceuticals's largest shareholding position with over 11.38Mn shares, representing 12.76% of total outstanding shares.
• Among the most significant buyers of Amylyx Pharmaceuticals during September 2025 were FMR LLC (8.33Mn), Commodore Capital LP (4.08Mn), First Light Asset Management, LLC (3.36Mn), JANUS HENDERSON GROUP PLC (2.52Mn), Almitas Capital LLC (2.12Mn).
• Leading sellers of Amylyx Pharmaceuticals stock in September 2025 included CITADEL ADVISORS LLC (2.52Mn), Nantahala Capital Management, LLC (2.00Mn), ADAGE CAPITAL PARTNERS GP, L.L.C. (1.98Mn), Point72 Asset Management, L.P. (1.75Mn), MILLENNIUM MANAGEMENT LLC (1.09Mn).
• The top 10 institutional holders of Amylyx Pharmaceuticals for the quarter ending September 2025 included FMR LLC (11.38Mn), PERCEPTIVE ADVISORS LLC (8.95Mn), BlackRock, Inc. (7.14Mn), ADAGE CAPITAL PARTNERS GP, L.L.C. (6.82Mn), TCG Crossover Management, LLC (6.24Mn), VANGUARD GROUP INC (5.27Mn), Saturn V Capital Management LP (4.60Mn), Almitas Capital LLC (4.25Mn), Commodore Capital LP (4.08Mn), First Light Asset Management, LLC (3.36Mn).