Altimmune, Inc. (ALT) Institutional Ownership

Ownership Summary

A total of 176 institutions have reported a stake in Altimmune, Inc. (NASDAQ:ALT) as of December 2025, according to recent 13F filings with the SEC.

• These investors collectively held 70.9% of the company's total shares outstanding in December 2025, up from 53.7% in September 2025.
• On a quarter-over-quarter basis, institutional holdings shifted by 37.01%, with a year-over-year a decrease of 1.12% in the count of filers.
• A review of institutional activity for Altimmune shows 119 of 176 filers increasing their positions, while 26 reduced their stake, and 31 remained unchanged.
• The aggregate institutional position in Altimmune now stands at 55.62Mn shares as of December 2025, after investors increased their holdings (up by 15.02Mn shares quarter on quarter which is up 14.76Mn shares year over year).
• BlackRock, Inc. continues to be the largest institutional holder of Altimmune as of December 31, 2025, with a position of 9.70Mn shares, representing 12.37% of the company's outstanding stock.
• Among the most significant buyers of Altimmune during December 2025 were BlackRock, Inc. (3.33Mn), VANGUARD GROUP INC (3.12Mn), JANE STREET GROUP, LLC (1.64Mn), STATE STREET CORP (1.52Mn), Nuveen, LLC (1.04Mn).
• Leading sellers of Altimmune stock in December 2025 included TWO SIGMA INVESTMENTS, LP (731.16K), TWO SIGMA ADVISERS, LP (634.50K), Squarepoint Ops LLC (549.75K), ExodusPoint Capital Management, LP (166.26K), MILLENNIUM MANAGEMENT LLC (160.20K).
• The top 10 institutional holders of Altimmune for the quarter ending December 2025 included BlackRock, Inc. (9.70Mn), VANGUARD GROUP INC (9.49Mn), STATE STREET CORP (5.12Mn), GEODE CAPITAL MANAGEMENT, LLC (2.29Mn), TANG CAPITAL MANAGEMENT LLC (2.13Mn), JANE STREET GROUP, LLC (2.05Mn), SUSQUEHANNA INTERNATIONAL GROUP, LLP (1.37Mn), MORGAN STANLEY (1.36Mn), GOLDMAN SACHS GROUP INC (1.35Mn), D. E. Shaw & Co., Inc. (1.34Mn).