Altimmune Inc
Ownership
Ownership Structure
Who owns Altimmune Inc (ALT)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 84.5% of the shares are freely tradable; institutional investors hold 57.8%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 10.48 | 20,385,284 | +59.3 | 06/30/2026 |
| Deep Track Capital, LP | 9.90 | 19,250,000 | +0.0 | 06/30/2026 |
| State Street Corp | 6.22 | 12,098,540 | +69.3 | 06/30/2026 |
| TCG Crossover Management, LLC | 5.14 | 10,000,000 | +0.0 | 06/30/2026 |
| Vanguard Capital Management, LLC | 4.20 | 8,177,752 | +44.5 | 06/30/2026 |
| Vanguard Portfolio Management, LLC | 3.77 | 7,330,265 | +36.2 | 06/30/2026 |
| Marshall Wace Asset Management Ltd | 3.52 | 6,841,055 | +70.3 | 06/30/2026 |
| Viking Global Investors LP | 3.44 | 6,700,000 | +0.0 | 06/30/2026 |
| RA Capital Management, LLC | 3.34 | 6,500,000 | +0.0 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.96 | 5,748,771 | +0.0 | 08/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Roberts M Scot | Chief Scientific Officer | 113,699 | 227,398 $ | Jul 31, 2026 | direct |
| Durso Jerome Benedict | President and CEO | 62,500 | 125,000 $ | Aug 13, 2026 | direct |
| Weaver Gregory L | Chief Financial Officer | 49,927 | 99,854 $ | Oct 1, 2026 | direct |
| Arbet-Engels Christophe | Chief Medical Officer | 24,821 | 49,642 $ | Oct 1, 2026 | direct |
| Richardson Linda M | Chief Commercial Officer | 17,174 | 34,348 $ | Sep 16, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Oct 1, 2026 | Arbet-Engels Christophe | Chief Medical Officer | Other | 12,679 | 2.76 | 34,994 |
| Oct 1, 2026 | Arbet-Engels Christophe | Chief Medical Officer | Other | 37,500 | 0.00 | – |
| Oct 1, 2026 | Weaver Gregory L | Chief Financial Officer | Other | 4,379 | 2.76 | 12,086 |
| Oct 1, 2026 | Weaver Gregory L | Chief Financial Officer | Other | 14,475 | 0.00 | – |
| Sep 16, 2026 | Richardson Linda M | Chief Commercial Officer | Other | 6,826 | 3.24 | 22,116 |
| Sep 16, 2026 | Richardson Linda M | Chief Commercial Officer | Other | 24,000 | 0.00 | – |
| Aug 13, 2026 | Durso Jerome Benedict | President and CEO | Buy | 15,000 | 2.95 | 44,250 |
| Jul 31, 2026 | Roberts M Scot | Chief Scientific Officer | Other | 875 | 2.41 | 2,112 |
| Jul 31, 2026 | Weaver Gregory L | Chief Financial Officer | Other | 1,753 | 2.41 | 4,232 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: October 30, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.