Altimmune (ALT) CFO acquires 1,753 shares via employee stock purchase plan

Rhea-AI Filing Summary

Altimmune, Inc. reported that Chief Financial Officer Gregory L. Weaver acquired 1,753 shares of common stock on July 31, 2026 through participation in the company’s 2019 Employee Stock Purchase Plan. The shares were bought at $2.414 per share, equal to 85% of that day’s closing price, for the ESPP period from February 1 to July 31, 2026. Following this plan purchase, Weaver directly holds 39,831 shares of Altimmune common stock.

Insider Trade Summary

Net Buyer: 1,753 shares

Net Buy 1 txn

Insider WEAVER GREGORY L

Role Chief Financial Officer

Type	Security	Shares	Price	Value
Grant/Award	Common Stock, par value $0.0001 F1, F2	1,753	$2.414	$4K

Holdings After Transaction: Common Stock, par value $0.0001 — 39,831 shares (Direct)

Footnotes (2)

1. F1. These shares were purchased due to participation by the reporting individual in the Issuer's 2019 Employee Stock Purchase Plan ("ESPP"). It pertains to the ESPP purchase period from February 1, 2026 through July 31, 2026.
2. F2. In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the Issuer's common stock on July 31, 2026.

Key Figures

Shares acquired: 1,753 shares Purchase price: $2.414 per share Ownership after transaction: 39,831 shares +2 more

5 metrics

Shares acquired 1,753 shares Common stock purchased on July 31, 2026 under 2019 ESPP

Purchase price $2.414 per share ESPP purchase price on July 31, 2026

Ownership after transaction 39,831 shares Directly owned Altimmune common stock following ESPP purchase

ESPP discount 85% of closing price ESPP shares priced at 85% of July 31, 2026 closing price

ESPP period February 1, 2026 to July 31, 2026 Purchase period to which the reported ESPP acquisition relates

Key Terms

Employee Stock Purchase Plan, ESPP, closing price, par value

4 terms

Employee Stock Purchase Plan financial

"participation by the reporting individual in the Issuer's 2019 Employee Stock Purchase Plan"

An employee stock purchase plan is a company program that lets workers buy shares through small payroll deductions, often at a discount to the market price and after a set offering period. Think of it like a workplace savings plan that turns into ownership: it encourages employees to share in the company’s success and can create predictable buying or selling of stock that investors watch because it affects supply, demand and employee incentives.

ESPP financial

"It pertains to the ESPP purchase period from February 1, 2026 through July 31, 2026."

An Employee Stock Purchase Plan (ESPP) is a company program that lets employees buy the company’s shares at a reduced price, usually by setting aside a small portion of their pay over time. It matters to investors because it encourages employees to own part of the business—like giving staff a discounted membership— which can boost commitment and performance, while also potentially increasing the number of shares available and affecting shareholder value.

closing price financial

"based on 85% of the closing price of the Issuer's common stock on July 31, 2026"

par value financial

"Common Stock, par value $0.0001"

Par value is the fixed amount printed on a bond or stock that represents its original value when issued. It’s like the face value of a coin or bill—what the issuer promises to pay back or the starting price of a stock—though it often doesn’t change with market prices. It matters because it helps determine certain financial details, like how much the company will pay back at maturity.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Form 4 Insider Transactions: What Each Field Means →

Available on EDGAR 08/03/2026 - 04:06 PM Accepted by SEC EDGAR 08/03/2026 - 04:05 PM Learn about SEC filing dates

FAQ

What insider stock transaction did Altimmune (ALT) disclose for July 31, 2026?

Altimmune disclosed that CFO Gregory L. Weaver acquired 1,753 shares of common stock on July 31, 2026. The acquisition occurred through the company’s 2019 Employee Stock Purchase Plan, reflecting routine participation rather than an open-market trade.

At what price did the Altimmune (ALT) CFO acquire shares under the ESPP?

The CFO acquired 1,753 shares at a price of $2.414 per share. This ESPP purchase price equals 85% of Altimmune’s common stock closing price on July 31, 2026, as specified under the plan’s terms.

How many Altimmune (ALT) shares does CFO Gregory Weaver own after this transaction?

After the ESPP purchase, CFO Gregory L. Weaver directly owns 39,831 shares of Altimmune common stock. This total includes the 1,753 shares acquired on July 31, 2026 under the 2019 Employee Stock Purchase Plan.

What plan was used for the Altimmune (ALT) insider share purchase?

The purchase was made through Altimmune’s 2019 Employee Stock Purchase Plan (ESPP). The reported 1,753 shares correspond to the ESPP purchase period from February 1, 2026 through July 31, 2026, ending on the transaction date.

How is the ESPP purchase price determined for Altimmune (ALT) shares?

Under Altimmune’s ESPP, the reported shares were bought at 85% of the closing price of the common stock on July 31, 2026. For this period, that formula produced a purchase price of $2.414 per share for the 1,753 shares acquired.

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)
07/31/2026

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	07/31/2026		A(1)		1,753	A	$2.414(2)	39,831	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. These shares were purchased due to participation by the reporting individual in the Issuer's 2019 Employee Stock Purchase Plan ("ESPP"). It pertains to the ESPP purchase period from February 1, 2026 through July 31, 2026.

2. In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the Issuer's common stock on July 31, 2026.

	/s/ Gregory Weaver	08/03/2026
	** 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)