InsiderTrades

Form 4 for ALT Altimmune, Inc.

Accepted 2026-09-17 16:05:29 ET · period of report 2026-09-16 · accession 0001595064-26-000002 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X Filed Traded Ticker Insider Title Type Price Qty Owned ΔOwn Value
D 2026-09-17 16:05 2026-09-16 ALT Richardson Linda M Chief Commercial Off M - OptEx $0.00 +24.0K 24.0K New $0
D 2026-09-17 16:05 2026-09-16 ALT Richardson Linda M Chief Commercial Off F - Tax $3.24 -6,826 17.2K -28% -$22.1K
D 2026-09-17 16:05 2026-09-16 ALT Richardson Linda M Chief Commercial Off M - OptEx $0.00 -24.0K 72.0K -25% $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock, par value $0.0001 2026-09-16 M A 24,000 $0.00 24,000 D — — (F1) Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested.
2 Common Common Stock, par value $0.0001 2026-09-16 F D 6,826 $3.24 17,174 D — — (F2) Vesting transaction: Shares surrendered to the Issuer solely to cover taxes associated with vesting of RSUs.
3 Derivative Restricted Stock Units 2026-09-16 M D 24,000 $0.00 72,000 D — · — to — 24,000 Common Stock, par value $0.0001 (F1) Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested. (F3) The RSUs become vested over four (4) years with 25% of the shares vesting on September 16, 2026, with the remainder vesting in equal annual installments for the following three (3) years, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date. (F3) The RSUs become vested over four (4) years with 25% of the shares vesting on September 16, 2026, with the remainder vesting in equal annual installments for the following three (3) years, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.