Institutional ownership · Form 13F
ALT institutional ownership
Altimmune, Inc. - Common Stock: reported institutional holdings as of 2026-06-30 (filed through 2026-08-31), aggregated by StockEyes from SEC Form 13F information tables. ALT is one of 2732 tickers in the validated publication set. Mapping coverage in this publication set: 4562 of 6046 universe tickers have at least one validated CUSIP mapping (75.5%). Latest-quarter filed value resolved to any listed ticker: 77.3%; resolved to this universe: 77.2%.
ALT: change since the prior quarter's filings
More managers reported a position, with the count rising from 171 in the quarter ended 2026-03-31 to 210 in the quarter ended 2026-06-30 (+39, 22.8%). Total reported shares rose to 151,564,673 (+82,261,822, 118.7%), moving the same way as the manager count. Among the 18 managers listed as top holders in both quarters, the largest increases were BlackRock, Inc. (+7,590,007 shares) and STATE STREET CORP (+4,952,990 shares), among 14 managers who added shares, and the largest decreases were SUSQUEHANNA INTERNATIONAL GROUP, LLP (-594,878 shares) and TWO SIGMA INVESTMENTS, LP (-97,758 shares), among 4 managers who reduced shares. Deep Track Capital, LP (19,250,000 shares), TCG Crossover Management, LLC (10,000,000 shares) and 10 more entered the listed top holders; Alyeska Investment Group, L.P. (2,644,600 shares in the prior quarter), DIMENSIONAL FUND ADVISORS LP (1,045,926 shares in the prior quarter) and 10 more dropped out of the listed top holders.
New to 13F data? Read how to read a 13F filing, or see where institutions moved overall in the Smart Money Report.
Reported totals, quarter ended 2026-06-30
210 reporting managers held 151,564,673 shares, reported value $459,108,924 exactly as filed. Values are position values transcribed from the filings, not current market prices.
Reported quarter-over-quarter change (quarter ended 2026-03-31 to quarter ended 2026-06-30): reporting managers +39, reported shares +82,261,822 (+118.70%), reported value +116.49%. These changes compare two filing snapshots.
Shares outstanding cross-check: no current issuer share-count point passed the freshness filter for this ticker, so the gate relied on holder-count and scale checks. See the hub methodology.
ALT in this quarter's filings
Concentration check: the largest reported position, BlackRock, Inc. with 20,385,284 shares, is 13.4% of all shares reported for ALT this quarter. The five largest reporting managers together account for 46.1% of the reported total, so the headline total is spread across a broad manager base rather than a few holders.
Reported quarter-over-quarter change: the reporting-manager count rose by 39 versus the quarter ended 2026-03-31, and reported shares moved +118.70% (+82,261,822 shares). That is a comparison of two filing snapshots, not a record of trades on any single day.
Shares-outstanding cross-check: no current issuer share-count point passed the freshness filter for ALT, so the publication gate relied on holder-count scale, current-CUSIP validation, and quarter consistency for this ticker.
Largest reporting managers, ALT
| # | Manager | Shares | Value as filed | Share of reported total |
|---|---|---|---|---|
| 1 | BlackRock, Inc. | 20,385,284 | $61,971,264 | 13.4% |
| 2 | Deep Track Capital, LP | 19,250,000 | $58,520,000 | 12.7% |
| 3 | STATE STREET CORP | 12,098,540 | $36,779,562 | 8.0% |
| 4 | TCG Crossover Management, LLC | 10,000,000 | $30,400,000 | 6.6% |
| 5 | VANGUARD CAPITAL MANAGEMENT LLC | 8,177,752 | $24,860,366 | 5.4% |
| 6 | VANGUARD PORTFOLIO MANAGEMENT LLC | 7,330,265 | $22,284,006 | 4.8% |
| 7 | MARSHALL WACE, LLP | 6,841,055 | $20,796,808 | 4.5% |
| 8 | VIKING GLOBAL INVESTORS LP | 6,700,000 | $20,368,000 | 4.4% |
| 9 | RA CAPITAL MANAGEMENT, L.P. | 6,500,000 | $19,760,000 | 4.3% |
| 10 | GEODE CAPITAL MANAGEMENT, LLC | 5,011,314 | $15,238,163 | 3.3% |
| 11 | Woodline Partners LP | 3,400,312 | $10,336,948 | 2.2% |
| 12 | MILLENNIUM MANAGEMENT LLC | 3,309,122 | $10,059,731 | 2.2% |
| 13 | Nantahala Capital Management, LLC | 3,000,000 | $9,120,000 | 2.0% |
| 14 | Trails Edge Capital Partners, LP | 2,660,000 | $8,086,400 | 1.8% |
| 15 | Nuveen, LLC | 2,405,354 | $7,312,276 | 1.6% |
Manager names and figures are transcribed from each manager's own Form 13F information table. A manager listing shares in this snapshot does not mean it holds them today.
Reported change, 2026-03-31 to 2026-06-30
| Quarter ended | Filed through | Reporting managers | Reported shares | Value as filed |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-29 | 171 | 69,302,851 | $212,068,576 |
| 2026-06-30 | 2026-08-31 | 210 | 151,564,673 | $459,108,924 |
Every change figure on this page is a reported quarter-over-quarter change between filing snapshots. It is not real-time trading activity.
ALT reported totals over time
Quarter ended 2026-06-30: 210 reporting managers · 151,564,673 reported shares · $459,108,924 value as filed.
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Quarter-end 13F filed data, long positions only; filings arrive up to 45 days after quarter end.
CUSIPs behind the ALT total
The validated bridge mapped 1 current CUSIP(s) to ALT for this quarter: 02155H200. Option pseudo-CUSIPs, units, warrants, and preferred classes are excluded from these common-share totals. Mapping coverage in this publication set: 4562 of 6046 universe tickers have at least one validated CUSIP mapping (75.5%). Latest-quarter filed value resolved to any listed ticker: 77.3%; resolved to this universe: 77.2%.
What this page is and is not
Form 13F reports are quarterly holdings snapshots. Managers file up to about 45 days after quarter-end, so these figures describe reported positions as of the quarter-end date, not holdings today. 13F lists reportable long positions from managers above the SEC reporting threshold and omits short positions entirely.
This page is informational only. It is not investment advice, a recommendation, or a signal to buy or sell. Source: SEC Form 13F bulk data set for filings through 2026-08-31 (period ended 2026-06-30), joined to tickers through StockEyes' validated CUSIP bridge. Methodology and coverage are documented on the institutional ownership hub.
Insider transactions for ALT (officer and director buys and sells) are covered by InsiderTrace: insidertrace.com/stock/alt. StockEyes does not duplicate insider transaction tables.
Related StockEyes pages
Latest headlines tagged ALT are on the market news wire. Upcoming earnings and market dates are on the events calendar. The term itself is defined in the institutional investor glossary entry, and the research workflow behind pages like this one is walked through in how to research a stock and how to compare SEC filings.