Director John C. Vollmer updates Amentum Holdings (AMTM) stake after RSU vesting

Rhea-AI Filing Summary

Amentum Holdings director John C. Vollmer reported equity compensation activity involving the company’s common stock. On February 6, 2026, 11,564 restricted stock units converted into an equal number of common shares at a price of $0 per share, increasing his direct common stock holdings to 424,780 shares. On the same date, he was granted 5,062 additional restricted stock units at $0, which will vest on the date of the next annual meeting of stockholders. Following these transactions, Vollmer directly owned 429,842 shares of Amentum Holdings common stock, while the reported restricted stock unit award tied to this filing had a remaining balance of zero units after vesting.

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

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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^*

Vollmer John C.

(Last) (First) (Middle)

C/O AMENTUM HOLDINGS, INC.

4800 WESTFIELDS BOULEVARD, SUITE 400

(Street)

CHANTILLY VA 20151

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Amentum Holdings, Inc. [ AMTM ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
02/06/2026

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	02/06/2026		M		11,564	A	(1)	424,780(2)	D
Common Stock	02/06/2026		A		5,062(3)	A	$0	429,842	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
Restricted Stock Units	(4)	02/06/2026		M			11,564	(5)	(5)	Common Stock	11,564	$0	0	D

Explanation of Responses:

1. Represents distribution of AMTM common stock upon vesting of restricted stock units.

2. Reflects a non-reportable transaction for shares transferred from the pro-rata distribution in-kind by Amentum Joint Venture LP to its partners for no consideration at the time of the transaction.

3. The restricted stock units shall vest on the date of the next annual meeting of stockholders of the Issuer.

4. Each restricted stock unit represents a contingent right to receive one share of AMTM common stock.

5. The restricted stock units awarded vested on February 6, 2026.

Remarks:

	/s/ Indira Lall, Attorney-in-fact	02/10/2026
	** 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 transactions did John C. Vollmer report at Amentum Holdings (AMTM)?

John C. Vollmer reported the vesting of 11,564 restricted stock units into common stock and the grant of 5,062 new restricted stock units. Both transactions occurred on February 6, 2026, at a price of $0 per share as part of his director equity compensation.

How many Amentum Holdings (AMTM) shares does John C. Vollmer own after this Form 4?

After the reported transactions, John C. Vollmer directly owned 429,842 shares of Amentum Holdings common stock. This reflects 11,564 shares received from vested restricted stock units plus his prior holdings, as well as the impact of the additional 5,062 restricted stock units granted that day.

What happened to John C. Vollmer’s restricted stock units in the February 6, 2026 transaction?

On February 6, 2026, 11,564 restricted stock units vested and were distributed as the same number of Amentum common shares. The Form 4 shows zero derivative securities remaining from this specific award after vesting, while 5,062 new restricted stock units were granted the same day.

At what price were John C. Vollmer’s Amentum equity awards reported on this Form 4?

Both the 11,564 common shares received from vested restricted stock units and the 5,062 newly granted restricted stock units were reported at a price of $0 per share. This reflects the nature of equity compensation awards rather than an open-market purchase or sale transaction.

When will John C. Vollmer’s new restricted stock units at Amentum Holdings (AMTM) vest?

The 5,062 restricted stock units granted to John C. Vollmer on February 6, 2026 will vest on the date of Amentum Holdings’ next annual meeting of stockholders. Each restricted stock unit represents a contingent right to receive one share of Amentum common stock upon vesting.

What does the Form 4 say about the nature of Amentum’s restricted stock units reported for John C. Vollmer?

Each restricted stock unit represents a contingent right to receive one share of Amentum common stock. The filing explains that 11,564 units vested on February 6, 2026, resulting in a distribution of the same number of common shares to John C. Vollmer as part of his director compensation.