Altimmune (NASDAQ: ALT) CEO buys 20,000 shares in open market

Rhea-AI Filing Summary

Altimmune, Inc. director, President and CEO Jerome Benedict Durso reported an open-market purchase of 20,000 shares of common stock. The shares were bought at a weighted average price of $3.5395 per share in multiple trades between $3.53 and $3.55.

Following this transaction, Durso now directly owns 32,500 shares of Altimmune common stock. The purchase reflects an increase in his direct equity stake through open-market buying.

Insider Trade Summary

Net Buyer: 20,000 shares ($70,790)

Net Buy 1 txn

Insider Durso Jerome Benedict

Role President and CEO

Bought 20,000 shs ($71K)

Type	Security	Shares	Price	Value
Purchase	Common Stock, par value $0.0001	20,000	$3.5395	$71K

Holdings After Transaction: Common Stock, par value $0.0001 — 32,500 shares (Direct)

Footnotes (1)

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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 MD 20878

(City) (State) (Zip)

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

3. Date of Earliest Transaction (Month/Day/Year)
03/06/2026

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

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

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

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	03/06/2026		P		20,000	A	$3.5395(1)	32,500	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:

1. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.5300 to $3.5500, inclusive. The reporting person undertakes to provide to Altimmune, Inc., any security holder of Altimmune, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote.

	/s/ Gregory Weaver, as Attorney-in-Fact	03/09/2026
	** 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.

FAQ

What insider transaction did Altimmune (ALT) report for Jerome Durso?

Altimmune reported that CEO and director Jerome Benedict Durso bought 20,000 shares of common stock in an open-market purchase. The transaction was reported on a Form 4 insider filing and involved non-derivative common stock with a par value of $0.0001 per share.

At what price did the Altimmune CEO buy the 20,000 ALT shares?

Jerome Durso bought the 20,000 shares at a $3.5395 weighted average price. According to the filing footnote, the purchases occurred in multiple trades at prices ranging from $3.53 to $3.55 per share, inclusive, in the open market.

How many Altimmune (ALT) shares does Jerome Durso own after this Form 4 trade?

After the reported transaction, Jerome Durso directly owns 32,500 shares of Altimmune common stock. The Form 4 indicates this total as his shares beneficially owned following the reported transaction, reflecting his direct ownership position after the 20,000-share purchase.

Was the Altimmune (ALT) CEO’s Form 4 trade a buy or a sell?

The Form 4 shows that Altimmune CEO Jerome Durso executed a buy transaction. It is coded as “P” for purchase and described as an open-market purchase, with no shares reported as sold or otherwise disposed of in this filing.

What does the Form 4 footnote say about the Altimmune CEO’s purchase price range?

The footnote explains that the reported $3.5395 price is a weighted average. The 20,000 shares were purchased in multiple transactions at prices ranging from $3.53 to $3.55, and full trade-by-trade details are available upon request to Altimmune or regulators.