Company · Ownership research

Altimmune, Inc. ALT

CIK 0001326190 · CUSIP 02155H200

Insider trading Initial holdings Institutional holders

Quarter-end disclosures, not live holdings.

Several CUSIPs are reported for this company; this page shows CUSIP 02155H200 (ALT), not CUSIP 02155H900 (ALT), CUSIP 02155H950 (ALT), and does not merge CUSIPs.

This page lists the top 20 of 210 rows by value; the complete set is available through the API.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	BlackRock, Inc. CIK 2012383 · View history	$61.97M 20,385,284 shares	0.00%	+7.59M(+59.30%)Added	SEC filing ↗ Aug 7, 2026	▾
02	Deep Track Capital, LP CIK 1856083 · View history	$58.52M 19,250,000 shares	0.86%	+19.25MNew	SEC filing ↗ Aug 14, 2026	▾
03	STATE STREET CORP CIK 93751 · Amended · View history	$36.78M 12,098,540 shares	0.00%	+4.95M(+69.30%)Added	SEC filing ↗ Sep 22, 2026	▾
04	TCG Crossover Management, LLC CIK 1839948 · View history	$30.40M 10,000,000 shares	0.73%	+10.00MNew	SEC filing ↗ Aug 14, 2026	▾
05	VANGUARD CAPITAL MANAGEMENT LLC CIK 2100119 · View history	$24.86M 8,177,752 shares	0.00%	+2.52M(+44.50%)Added	SEC filing ↗ Aug 13, 2026	▾
06	VANGUARD PORTFOLIO MANAGEMENT LLC CIK 2100121 · View history	$22.28M 7,330,265 shares	0.00%	+1.95M(+36.20%)Added	SEC filing ↗ Aug 13, 2026	▾
07	MARSHALL WACE, LLP CIK 1318757 · View history	$20.80M 6,841,055 shares	0.02%	+2.82M(+70.30%)Added	SEC filing ↗ Aug 13, 2026	▾
08	VIKING GLOBAL INVESTORS LP CIK 1103804 · View history	$20.37M 6,700,000 shares	0.06%	+6.70MNew	SEC filing ↗ Aug 14, 2026	▾
09	RA CAPITAL MANAGEMENT, L.P. CIK 1346824 · View history	$19.76M 6,500,000 shares	0.17%	+6.50MNew	SEC filing ↗ Aug 14, 2026	▾
10	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$15.24M 5,011,314 shares	0.00%	+1.90M(+61.30%)Added	SEC filing ↗ Aug 12, 2026	▾
11	Woodline Partners LP CIK 1784547 · View history	$10.34M 3,400,312 shares	0.03%	+3.40MNew	SEC filing ↗ Aug 14, 2026	▾
12	MILLENNIUM MANAGEMENT LLC CIK 1273087 · View history	$10.06M 3,309,122 shares	0.01%	+50.93K(+1.60%)Added	SEC filing ↗ Aug 14, 2026	▾
13	Trails Edge Capital Partners, LP CIK 2077247 · View history	$8.09M 2,660,000 shares	1.28%	+2.66MNew	SEC filing ↗ Aug 14, 2026	▾
14	Nuveen, LLC CIK 1871926 · View history	$7.31M 2,405,354 shares	0.00%	+70.75K(+3.00%)Added	SEC filing ↗ Aug 11, 2026	▾
15	TWO SIGMA INVESTMENTS, LP CIK 1179392 · View history	$7.24M 2,381,142 shares	0.01%	-97.76K(-3.90%)Reduced	SEC filing ↗ Aug 14, 2026	▾
16	GOLDMAN SACHS GROUP INC CIK 886982 · View history	$6.73M 2,214,450 shares	0.00%	+863.80K(+64.00%)Added	SEC filing ↗ Aug 14, 2026	▾
17	GREAT POINT PARTNERS LLC CIK 1281446 · View history	$5.29M 1,741,232 shares	1.25%	+1.74MNew	SEC filing ↗ Aug 14, 2026	▾
18	NORTHERN TRUST CORP CIK 73124 · View history	$4.86M 1,599,226 shares	0.00%	+602.50K(+60.40%)Added	SEC filing ↗ Aug 13, 2026	▾
19	Weiss Asset Management LP CIK 1357550 · View history	$4.65M 1,530,803 shares	0.05%	+1.53MNew	SEC filing ↗ Aug 14, 2026	▾
20	Nantahala Capital Management, LLC CIK 1472322 · Amended · View history	$4.56M 1,500,000 shares	0.28%	+1.50MNew	SEC filing ↗ Aug 19, 2026	▾

Showing 20 / 210 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

210

Cancelled or null records excluded

Disclosed shares

150,049,739

Not deduplicated across managers

Disclosed value

$456.15M

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

Altimmune, Inc. · Q2 2026

Explore all 210 reporting institutions.

This page includes 20 of 210 reporting institutions. Log in to look up the full history beyond 3 years, use advanced screening & filtering, download CSV, and get the complete set through the Akkru API.

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Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.