Altimmune (NASDAQ: ALT) CEO adds 15,000 shares in open-market buy

Rhea-AI Filing Summary

Altimmune, Inc. President and CEO Jerome Benedict Durso reported an open-market purchase of 15,000 shares of the company’s common stock at $3.14 per share.

Following this transaction, his directly held Altimmune common stock position increased to 47,500 shares.

Insider Trade Summary

Net Buyer: 15,000 shares ($47,100)

Net Buy 1 txn

Insider Durso Jerome Benedict

Role President and CEO

Bought 15,000 shs ($47K)

Type	Security	Shares	Price	Value
Purchase	Common Stock, par value $0.0001	15,000	$3.14	$47K

Holdings After Transaction: Common Stock, par value $0.0001 — 47,500 shares (Direct)

Footnotes (1)

Key Figures

Shares purchased: 15,000 shares Purchase price: $3.14 per share Post-transaction holdings: 47,500 shares +1 more

4 metrics

Shares purchased 15,000 shares Open-market purchase of common stock

Purchase price $3.14 per share Price paid in the reported transaction

Post-transaction holdings 47,500 shares Direct ownership after the trade

Transaction date April 1, 2026 Date of open-market purchase

Key Terms

open-market purchase, Common Stock, par value $0.0001, Form 4

3 terms

open-market purchase financial

"transaction_action: "open-market purchase""

An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.

Common Stock, par value $0.0001 financial

"security_title: "Common Stock, par value $0.0001""

Form 4 regulatory

"INSIDER FILING DATA (Form 4)"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Durso Jerome Benedict

(Last) (First) (Middle)

910 CLOPPER ROAD

SUITE 201S

(Street)

GAITHERSBURG MARYLAND 20878

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Altimmune, Inc. [ ALT ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/01/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.0001	04/01/2026		P		15,000	A	$3.14	47,500	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

	/s/ Gregory Weaver, as Attorney-in-Fact	04/01/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Altimmune (ALT) report on Form 4?

Altimmune reported that President and CEO Jerome Benedict Durso made an open-market purchase of common stock. He bought 15,000 Altimmune shares, increasing his direct ownership to 47,500 shares after the transaction.

How many Altimmune (ALT) shares did the CEO buy and at what price?

Jerome Benedict Durso purchased 15,000 shares of Altimmune common stock. The reported open-market purchase price was $3.14 per share, as disclosed in the Form 4 insider trading report.

What is the Altimmune (ALT) CEO’s total direct shareholding after this Form 4 trade?

After the reported transaction, Altimmune President and CEO Jerome Benedict Durso directly owns 47,500 shares of the company’s common stock, according to the updated post-transaction holdings listed in the Form 4.

Was the latest Altimmune (ALT) insider transaction a purchase or a sale?

The latest reported insider transaction was a purchase. Form 4 shows Jerome Benedict Durso executed an open-market buy of 15,000 Altimmune common shares rather than selling or disposing of shares.

What type of security did the Altimmune (ALT) CEO acquire in this filing?

Jerome Benedict Durso acquired Altimmune’s Common Stock, par value $0.0001 per share. The filing specifies this as a non-derivative security purchased in an open-market transaction on the reported date.

On what date did the Altimmune (ALT) CEO complete the reported share purchase?

The Form 4 states that Jerome Benedict Durso’s open-market purchase of 15,000 Altimmune common shares occurred on April 1, 2026, with the transaction and resulting holdings recorded as of that date.