Stephen A. Arnette - 15 Nov 2025 Form 4 Insider Report for Amentum Holdings, Inc. (AMTM)

Role
Chief Operating Officer
Signature
/s/ Mark Esposito, Attorney-in-Fact
Issuer symbol
AMTM
Transactions as of
15 Nov 2025
Net transactions value
-$102,648
Form type
4
Filing time
18 Nov 2025, 16:57:11 UTC
Previous filing
10 Nov 2025
Next filing
19 Dec 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 18 Nov 2025 0001919492

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction AMTM Common Stock Options Exercise +5,758 +18% 37,386 15 Nov 2025 Direct F1
transaction AMTM Common Stock Tax liability $30,964 -1,403 -3.8% $22.07 35,983 15 Nov 2025 Direct F2
transaction AMTM Common Stock Options Exercise +5,053 +14% 41,036 16 Nov 2025 Direct F1
transaction AMTM Common Stock Tax liability $27,168 -1,231 -3% $22.07 39,805 16 Nov 2025 Direct F2
transaction AMTM Common Stock Options Exercise +3,681 +9.2% 43,486 16 Nov 2025 Direct F1
transaction AMTM Common Stock Tax liability $19,797 -897 -2.1% $22.07 42,589 16 Nov 2025 Direct F2
transaction AMTM Common Stock Options Exercise +4,596 +11% 47,185 16 Nov 2025 Direct F1
transaction AMTM Common Stock Tax liability $24,718 -1,120 -2.4% $22.07 46,065 16 Nov 2025 Direct F2

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 -5,758 -33% $0.000000 11,515 15 Nov 2025 Common Stock 5,758 Direct F1, F3, F4
transaction AMTM Restricted Stock Units Options Exercise $0 -5,053 -50% $0.000000 5,053 16 Nov 2025 Common Stock 5,053 Direct F1, F3, F5
transaction AMTM Restricted Stock Units Options Exercise $0 -3,681 -100% $0.000000 0 16 Nov 2025 Common Stock 3,681 Direct F1, F3, F5
transaction AMTM Restricted Stock Units Options Exercise $0 -4,596 -100% $0.000000 0 16 Nov 2025 Common Stock 4,596 Direct F1, F3, 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 Each restricted stock unit represents a contingent right to receive one share of AMTM common stock.
F4 The restricted stock units awarded vested on November 15, 2025.
F5 The restricted stock units awarded vested on November 16, 2025.