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Altimmune, Inc.

ALT
Exchange
Nasdaq
Industry
Pharmaceutical Preparations
SEC CIK
0001326190

In the last 90 days, Altimmune, Inc. insiders filed 1 open-market purchase and 0 sales; 210 institutions reported holding it in 13F filings for Q2 2026, worth $460.7M in total; Viking Global Investors is the only superinvestor holding it.

Key figures

Insider buysLast 90 days, $44.3K in total
1
Insider sellsOpen market, last 90 days
0
13F holdersQ2 2026, +40 vs. previous quarter
210
13F valueReported value at the end of Q2 2026
$460.7M
Superinvestors holdingAt the end of Q2 2026
1

Price chart

Superinvestors holding ALT, Q2 2026

1 superinvestor reports holding Altimmune, Inc. on Form 13F. Percentages are the stock's share of each portfolio.

Go to the superinvestors tab

Viking Global Investors

Andreas Halvorsen

0.1%

Altimmune, Inc.'s share of the portfolio

Shares
6,700,000
Value
$20.4M

Latest insider trades

Open-market purchases and sales by Altimmune, Inc. insiders from Form 4, newest first.

See all insider trades
Insider trades
Filed (ET)Trade dateFiling delayInsiderTransactionSharesAvg priceValueHolding changeFlags
Aug 13, 2026 (view filing)4:05 PM ETAug 13Same dayDurso Jerome BenedictPresident and CEOPPurchaseCommon Stock, par value $0.0001+15.0K$2.95+$44.3K+31.6%62.5K after
Apr 6, 2026 (view filing)Apr 6Same dayGill JohnDirectorPPurchaseCommon Stock, par value $0.0001+9.20K$3.41+$31.4K+73.6%21.7K after
Apr 1, 2026 (view filing)Apr 1Same dayDurso Jerome BenedictPresident and CEOPPurchaseCommon Stock, par value $0.0001+15.0K$3.14+$47.1K+46.2%47.5K after
Apr 1, 2026 (view filing)Apr 1Same dayWeaver Gregory LChief Financial OfficerPPurchaseCommon Stock, par value $0.0001+10.0K$3.15+$31.5K+35.6%38.1K after
Mar 9, 2026 (view filing)Mar 63 daysDurso Jerome BenedictPresident and CEOPPurchaseCommon Stock, par value $0.0001+20.0K$3.54+$70.8K+160.0%32.5K after
Mar 9, 2026 (view filing)Mar 63 daysWeaver Gregory LChief Financial OfficerPPurchaseCommon Stock, par value $0.0001+5.00K$3.54+$17.7K+21.7%28.1K after
Jan 9, 2026 (view filing)Jan 81 dayPisano WayneDirectorPPurchaseCommon Stock, par value $0.0001+5.00K$4.08+$20.4K+58.8%13.5K after
Jan 5, 2026 (view filing)Jan 5Same daySohn Catherine A.DirectorPPurchaseCommon Stock, par value $0.0001+500$4.24+$2.12K+50.0%1.50K after
Dec 29, 2025 (view filing)Dec 29Same dayJorkasky DianeDirectorPPurchaseCommon Stock, par value $0.0001+527$3.80+$2.00KNew position527 after
Dec 23, 2025 (view filing)Dec 23Same dayGill JohnDirectorPPurchaseCommon Stock, par value $0.0001+12.5K$4.10+$51.3KNew position12.5K after

Top 10 13F holders, Q2 2026

The largest institutional positions in Altimmune, Inc. at the end of Q2 2026; share changes are against Q1 2026.

See all 210 holders
Institutions holding ALT in Q2 2026
InstitutionSharesValue% of portfolioChange in sharesAction
BlackRock, Inc.20,385,284$62.0M0.00%+7,590,007+59.3%Added
Deep Track Capital, LP19,250,000$58.5M0.86%+19,250,000New
State Street Corp12,098,540$36.8M0.00%+4,952,990+69.3%Added
TCG Crossover Management, LLC10,000,000$30.4M0.73%+10,000,000New
Vanguard Capital Management LLC8,177,752$24.9M0.00%+2,519,703+44.5%Added
Vanguard Portfolio Management LLC7,330,265$22.3M0.00%+1,948,263+36.2%Added
Marshall Wace, LLP6,841,055$20.8M0.02%+2,823,154+70.3%Added
Viking Global Investors LPSuperinvestorViking Global Investors6,700,000$20.4M0.06%+6,700,000New
Ra Capital Management, L.P.6,500,000$19.8M0.17%+6,500,000New
Geode Capital Management, LLC5,011,314$15.2M0.00%+1,904,218+61.3%Added