Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in ALT held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 12.8M | $39.4M | +31.9% | 14.498% | 0.00% |
| 2 | STATE STREET CORP | 7.1M | $22.0M | +39.6% | 8.096% | 0.00% |
| 3 | VANGUARD CAPITAL MANAGEMENT LLC | 5.7M | $17.4M | β | 6.411% | 0.00% |
| 4 | VANGUARD PORTFOLIO MANAGEMENT LLC | 5.4M | $16.6M | β | 6.098% | 0.00% |
| 5 | MARSHALL WACE, LLP | 4.0M | $12.4M | +335.4% | 4.553% | 0.01% |
| 6 | MILLENNIUM MANAGEMENT LLC | 3.3M | $10.0M | +1471.1% | 3.692% | 0.01% |
| 7 | GEODE CAPITAL MANAGEMENT, LLC | 3.1M | $9.6M | +35.5% | 3.521% | 0.00% |
| 8 | Alyeska Investment Group, L.P. | 2.6M | $8.1M | β | 2.996% | 0.02% |
| 9 | TWO SIGMA INVESTMENTS, LP | 2.5M | $7.6M | +95.9% | 2.809% | 0.01% |
| 10 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 2.4M | $7.5M | -33.6% | 2.767% | 0.00% |
| 11 | Nuveen, LLC | 2.3M | $7.2M | +87.6% | 2.645% | 0.00% |
| 12 | GOLDMAN SACHS GROUP INC | 1.4M | $4.2M | +0.1% | 1.530% | 0.00% |
| 13 | DIMENSIONAL FUND ADVISORS LP | 1.0M | $3.2M | +268.7% | 1.185% | 0.00% |
| 14 | NORTHERN TRUST CORP | 997K | $3.1M | +39.2% | 1.129% | 0.00% |
| 15 | CITADEL ADVISORS LLC | 982K | $3.0M | -58.0% | 1.113% | 0.00% |
| 16 | UBS Group AG | 905K | $2.8M | -1.4% | 1.025% | 0.00% |
| 17 | VANGUARD FIDUCIARY TRUST CO | 869K | $2.7M | β | 0.985% | 0.00% |
| 18 | MORGAN STANLEY | 775K | $2.4M | -43.0% | 0.878% | 0.00% |
| 19 | D. E. Shaw & Co., Inc. | 727K | $2.2M | -45.9% | 0.824% | 0.00% |
| 20 | FMR LLC | 674K | $2.1M | +19.5% | 0.764% | 0.00% |
| 21 | TANG CAPITAL MANAGEMENT LLC | 666K | $2.1M | -68.8% | 0.755% | 0.10% |
| 22 | Point72 Asset Management, L.P. | 665K | $2.0M | β | 0.754% | 0.00% |
| 23 | SCHRODER INVESTMENT MANAGEMENT GROUP | 668K | $1.9M | +42.4% | 0.757% | 0.00% |
| 24 | BANK OF AMERICA CORP /DE/ | 570K | $1.8M | +48.6% | 0.646% | 0.00% |
| 25 | BNP PARIBAS ARBITRAGE, SA | 435K | $1.3M | +145.4% | 0.493% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in ALT β a direct measure of their conviction.
Filings activity in ALT during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 169 | 5.1% | 94.14% | +2.44 pp | $217M | +2.7% |
| Q4 2025 | 178 | +15% | 91.70% | +18.22 pp | $211M | +25% |
| Q3 2025 | 155 | 11% | 73.48% | +10.60 pp | $169M | +17% |
| Q2 2025 | 175 | +2.9% | 62.88% | 21.18 pp | $145M | 25% |
| Q1 2025 | 170 | 2.3% | 84.06% | 41.81 pp | $194M | 33% |
| Q4 2024 | 174 | +6.7% | 125.87% | +22.52 pp | $290M | +22% |
| Q3 2024 | 163 | 1.8% | 103.35% | 18.26 pp | $238M | 15% |
| Q2 2024 | 166 | β | 121.61% | β | $280M | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying ALT stock.
Based on Q1 2026 13F filings, institutional ownership of Altimmune, Inc. stands at 94.1%, held across 169 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of ALT, with approximately 12,795,277 shares worth $0.04B as of Q1 2026.
Yes β 5 widely-followed marquee investors appear among the top 25 institutional holders of ALT, including MILLENNIUM MANAGEMENT LLC, TWO SIGMA INVESTMENTS, LP, SUSQUEHANNA INTERNATIONAL GROUP, LLP, CITADEL ADVISORS LLC, Point72 Asset Management, L.P..
Our composite Smart Money Score for ALT is 71 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
33 institutions opened new positions in ALT during Q1 2026, while 42 fully exited. 61 added to existing positions and 74 trimmed.
ALT institutional ownership rose by 2.44 percentage points quarter-over-quarter, with a net change of -9 holders.
The top 10 institutions account for 69.5% of all reported 13F value in ALT, and the top 25 account for 88.8%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Altimmune, Inc. (ALT) Institutional Ownership