Altimmune (ALT) CFO adds 10,000 shares in open-market stock purchase

Rhea-AI Filing Summary

Altimmune, Inc. Chief Financial Officer Gregory L. Weaver completed an open-market purchase of 10,000 shares of common stock. The transaction, dated April 1, 2026, was executed at a weighted average price of $3.1499 per share and was made directly.

Following this purchase, Weaver directly owns 38,078 shares of Altimmune common stock. According to the footnote, the shares were bought in multiple trades, with prices ranging from $3.1450 to $3.1499 per share.

Insider Trade Summary

Net Buyer: 10,000 shares ($31,499)

Net Buy 1 txn

Insider WEAVER GREGORY L

Role Chief Financial Officer

Bought 10,000 shs ($31K)

Type	Security	Shares	Price	Value
Purchase	Common Stock, par value $0.0001	10,000	$3.1499	$31K

Holdings After Transaction: Common Stock, par value $0.0001 — 38,078 shares (Direct)

Footnotes (1)

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Key Figures

Shares purchased: 10,000 shares Weighted average price: $3.1499 per share Price range: $3.1450–$3.1499 per share +2 more

5 metrics

Shares purchased 10,000 shares Open-market buy on April 1, 2026

Weighted average price $3.1499 per share Price for 10,000-share purchase

Price range $3.1450–$3.1499 per share Range of individual trade prices

Shares owned after 38,078 shares Direct holdings post-transaction

Net buy shares 10,000 shares Net effect of reported transactions

Key Terms

open-market purchase, weighted average price, Common Stock, par value $0.0001

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.

weighted average price financial

"The price reported in Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

Common Stock, par value $0.0001 financial

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

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^*

WEAVER GREGORY L

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

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		10,000	A	$3.1499(1)	38,078	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 $3.1450 to $3.1499, 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	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 for its CFO?

Altimmune reported that CFO Gregory L. Weaver made an open-market purchase of 10,000 shares of common stock on April 1, 2026. The transaction increased his direct holdings and reflects a routine insider buy disclosed through a Form 4 filing.

How many Altimmune (ALT) shares does the CFO hold after this Form 4?

After the reported transaction, Altimmune CFO Gregory L. Weaver directly owns 38,078 shares of the company’s common stock. This figure reflects his position immediately following the 10,000-share open-market purchase disclosed in the Form 4.

At what price did Altimmune (ALT) CFO buy the 10,000 shares?

The 10,000 Altimmune shares were purchased at a weighted average price of $3.1499 per share. According to the footnote, individual trade prices ranged from $3.1450 to $3.1499, and full breakdowns are available upon request from the reporting person.

Was the Altimmune (ALT) CFO transaction a direct or indirect ownership change?

The Form 4 identifies the transaction as a direct ownership change for CFO Gregory L. Weaver. The purchased 10,000 common shares are held directly in his name, with no indication in the filing that they are owned through a separate entity or trust.

What type of security did the Altimmune (ALT) CFO purchase?

The CFO purchased Altimmune’s common stock, with a par value of $0.0001 per share. The Form 4 specifies this as a non-derivative security, meaning it is the underlying stock itself rather than an option, warrant, or other derivative instrument.