Stephen A. Arnette - Nov 17, 2025 Form 4 Insider Report for Amentum Holdings, Inc. (AMTM)

Role
Chief Operating Officer
Signature
/s/ Mark Esposito, Attorney-in-Fact
Stock symbol
AMTM
Transactions as of
Nov 17, 2025
Transactions value $
-$6,168
Form type
4
Date filed
11/19/2025, 05:36 PM
Previous filing
Nov 18, 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Arnette Stephen A Chief Operating Officer C/O AMENTUM HOLDINGS, INC., 4800 WESTFIELDS BOULEVARD, SUITE 400, CHANTILLY /s/ Mark Esposito, Attorney-in-Fact 2025-11-19 0001919492

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction AMTM Common Stock Options Exercise +1.18K +2.56% 47.2K Nov 17, 2025 Direct F1
transaction AMTM Common Stock Tax liability -$6.17K -287 -0.61% $21.49 47K Nov 17, 2025 Direct F2
transaction AMTM Common Stock Award $0 +46.8K +99.6% $0.00 93.7K Nov 17, 2025 Direct F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction AMTM Restricted Stock Units Options Exercise $0 -1.18K -100% $0.00 0 Nov 17, 2025 Common Stock 1.18K Direct F4, F5
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Represents distribution of AMTM common stock upon vesting of restricted stock units.
F2 Represents number of shares of AMTM common stock tendered for tax withholding upon vesting of restricted stock units.
F3 One-third of the restricted stock units shall vest on each of the first, second and third anniversaries of November 17, 2025.
F4 Each restricted stock unit represents a contingent right to receive one share of AMTM common stock.
F5 The restricted stock units awarded vested on November 17, 2025.