SCHEDULE: Vanguard Discloses 9.09% Stake in Altimmune Inc

The Vanguard Group reported a 9.09% beneficial ownership stake in Altimmune Inc common stock as of December 31, 2025.

Summary

• The Vanguard Group reported beneficial ownership of 9,491,159 shares of Altimmune Inc common stock.
• This ownership represents 9.09% of the total class of Altimmune Inc's common stock.
• Vanguard holds 744,210 shares with shared voting power and 9,491,159 shares with shared dispositive power.
• An internal realignment occurred at The Vanguard Group, Inc. on January 12, 2026, resulting in the company no longer performing portfolio management services or administering proxy voting directly.
• Following this realignment, certain Vanguard subsidiaries or business divisions are expected to report beneficial ownership separately (on a disaggregated basis) from The Vanguard Group, Inc.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this filing as neutral, as it is a routine disclosure of passive beneficial ownership by a large institutional investor and does not contain performance-related information about the issuer.

Positives

• A major institutional investor, The Vanguard Group, holds a significant 9.09% stake in Altimmune Inc, indicating a substantial passive investment.

Negatives

• No specific negatives related to Altimmune Inc's performance or operations are disclosed in this ownership filing.

Risks

• No risks related to Altimmune Inc are disclosed in this ownership filing.

Future Outlook

Following an internal realignment on January 12, 2026, The Vanguard Group, Inc. anticipates that certain subsidiaries or business divisions will report beneficial ownership separately from The Vanguard Group, Inc. in reliance on SEC Release No. 34-39538.

Management Comments

• "The Vanguard Group, Inc. anticipates that certain subsidiaries or business divisions of subsidiaries of The Vanguard Group, Inc., that currently have, or are deemed to have, beneficial ownership with The Vanguard Group, Inc., will report beneficial ownership separately (on a disaggregated basis) from The Vanguard Group, Inc. in reliance on such release."
• "These subsidiaries and/or business divisions pursue the same investment strategies as previously pursued by The Vanguard Group, Inc. prior to the realignment."
• "The securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities."

Industry Context

StockSavvy.ai notes that Schedule 13G filings are standard disclosures for passive institutional investors holding more than 5% of a company's stock. The Vanguard Group is one of the world's largest asset managers, and its significant stake in Altimmune Inc reflects a typical passive investment strategy within its broad portfolio.

Management Changes

Stakeholder Impact

• Shareholders: The filing confirms a significant institutional holder, which can be viewed as a sign of stability or institutional interest.
• Vanguard Clients: Clients of The Vanguard Group, Inc., including investment companies and other managed accounts, are the ultimate beneficial owners of the reported securities.

Next Steps

• Certain subsidiaries or business divisions of The Vanguard Group, Inc. are expected to report beneficial ownership separately from The Vanguard Group, Inc. in future filings.

Key Dates

Keywords

Altimmune Inc, Vanguard Group, Common Stock, Beneficial Ownership, Institutional Investor, Schedule 13G, Passive Investment