Sean Thomas Mullen

CIK: 0002034388

Transaction Breakdown

Open Market Buys (P)0 (0.0%)

High conviction signal

Open Market Sales (S)0 (0.0%)

Position reduction

Option Exercises (M)3 (30.0%)

Derivative conversions

Awards (A)4 (40.0%)

Compensation grants

Other (G, F, J, C, D, …)3 (30.0%)

Gifts, tax withholding, conversions, dispositions to the issuer and other codes

Companies & Roles (1)

AMTM

Amentum Holdings, Inc.

Officer

Discretionary Trading P&L

Holdings

Transaction History (10 total)

AMTM
Amentum Holdings, Inc.
May 6, 2026
Tax Payment(F)
Direct
2.8K shares at avg. $24.89$69K
AMTM
Amentum Holdings, Inc.
May 6, 2026
Exercise(M)
Direct
9.1K shares-
AMTM
Amentum Holdings, Inc.
Dec 17, 2025
Exercise(M)
Direct
9.3K shares-
AMTM
Amentum Holdings, Inc.
Dec 17, 2025
Tax Payment(F)
Direct
4.2K shares at avg. $28.67$120K
AMTM
Amentum Holdings, Inc.
Nov 17, 2025
Award(A)
Direct
17.8K shares-
AMTM
Amentum Holdings, Inc.
Nov 6, 2025
Tax Payment(F)
Direct
1.6K shares at avg. $21.79$35K
AMTM
Amentum Holdings, Inc.
Nov 6, 2025
Exercise(M)
Direct
4.8K shares-
AMTM
Amentum Holdings, Inc.
Dec 20, 2024
Award(A)
Restricted Stock Units
Direct
9.3K shares-
AMTM
Amentum Holdings, Inc.
Nov 6, 2024
Award(A)
Restricted Stock Units
Direct
18.1K shares-
AMTM
Amentum Holdings, Inc.
Nov 6, 2024
Award(A)
Restricted Stock Units
Direct
14.5K shares-

		Type	Shares	Price		Ownership
May 6, 2026	AMTM Amentum Holdings, Inc.	Tax Payment(F)	2,762	$24.89	$68,746	Direct
May 6, 2026	AMTM Amentum Holdings, Inc.	Exercise(M)	9,072	-	$0	Direct
Dec 17, 2025	AMTM Amentum Holdings, Inc.	Exercise(M)	9,298	-	-	Direct
Dec 17, 2025	AMTM Amentum Holdings, Inc.	Tax Payment(F)	4,194	$28.67	$120,242	Direct
Nov 17, 2025	AMTM Amentum Holdings, Inc.	Award(A)	17,817	-	-	Direct
Nov 6, 2025	AMTM Amentum Holdings, Inc.	Tax Payment(F)	1,621	$21.79	$35,322	Direct
Nov 6, 2025	AMTM Amentum Holdings, Inc.	Exercise(M)	4,838	-	-	Direct
Dec 20, 2024	AMTM Amentum Holdings, Inc.	Award(A) Restricted Stock Units	9,298	-	-	Direct
Nov 6, 2024	AMTM Amentum Holdings, Inc.	Award(A) Restricted Stock Units	18,145	-	-	Direct
Nov 6, 2024	AMTM Amentum Holdings, Inc.	Award(A) Restricted Stock Units	14,516	-	-	Direct

1-10 of 10 transactions

About Mullen Sean Thomas

Mullen Sean Thomas (SEC CIK 0002034388) files insider reports with the SEC as Chief Growth Officer of Amentum Holdings, Inc. (AMTM).

Signal8 holds 7 ownership filings by Mullen Sean Thomas (1 Form 3, 6 Form 4), filed between Sep 27, 2024 and May 7, 2026. Those filings report 10 transactions, from Nov 6, 2024 to May 6, 2026. Signal8's Form 4 history starts in Sep 2024.

The business address on Mullen Sean Thomas's filings is in CHANTILLY, VA.

Recent filings by Mullen Sean Thomas

May 6, 2026: Tax withholding of AMTM shares (Form 4, code F).
May 6, 2026: Option exercise of AMTM shares (Form 4, code M).
Dec 17, 2025: Option exercise of AMTM shares (Form 4, code M).
Dec 17, 2025: Tax withholding of AMTM shares (Form 4, code F).
Nov 17, 2025: Grant or award of AMTM shares (Form 4, code A).

Other insiders filing for Amentum Holdings, Inc. (AMTM)

Thompson Christopher M.T., Director
Heller John E., Chief Executive Officer
Johnson Travis Barton, Chief Financial Officer
Bruning Jill L, Chief Technology Officer
Arnette Stephen A, Chief Operating Officer
St. Mary Michele T, Chief Legal Officer & GC

How to read Form 4 transaction codes