AMTM SEC Filings: 8-K, 10-Q, S-3 & 424B – Amentum

Financials

TYPE

HEADLINE

FILED AT

10-Q

Form 10-Q - Quarterly report [Sections 13 or 15(d)]

Aug 11, 2026

10-Q

Form 10-Q - Quarterly report [Sections 13 or 15(d)]

May 12, 2026

10-Q

Form 10-Q - Quarterly report [Sections 13 or 15(d)]

Feb 10, 2026

10-K

Form 10-K - Annual report [Section 13 and 15(d), not S-K Item 405]

Nov 25, 2025

10-Q

Form 10-Q - Quarterly report [Sections 13 or 15(d)]

Aug 6, 2025

10-Q

Form 10-Q - Quarterly report [Sections 13 or 15(d)]

May 7, 2025

News

TYPE

HEADLINE

FILED AT

8-K

Amentum Holdings, Inc. Amends Employment Agreement for Executive Chair Steven J. Demetriou

Oct 2, 2026

8-K

Amentum Reports Third Quarter Fiscal Year 2026 Results

Aug 10, 2026

8-K

Amentum Reports Second Quarter Fiscal Year 2026 Results and Reaffirms Full Year Guidance

May 11, 2026

8-K

Amentum Holdings, Inc. Enters Into Amended Credit Agreement

Apr 28, 2026

8-K

Amentum Holdings, Inc. Stockholder Meeting Results

Feb 10, 2026

8-K

Amentum Reports Q1 Fiscal Year 2026 Results and Reaffirms Full Year Guidance

Feb 9, 2026

Prospectus

TYPE

HEADLINE

FILED AT

424B4

Form 424B4 - Prospectus [Rule 424(b)(4)]

Mar 12, 2025

Registrations

TYPE

HEADLINE

FILED AT

S-3ASR

Form S-3ASR - Automatic shelf registration statement of securities of well-known seasoned issuers

Oct 1, 2025

S-1

Form S-1 - General form for registration of securities under the Securities Act of 1933

Mar 10, 2025

DRS

Form DRS - Draft Registration Statement

Jan 21, 2025

S-8

Form S-8 - Securities to be offered to employees in employee benefit plans

Nov 8, 2024

S-8

Form S-8 - Securities to be offered to employees in employee benefit plans

Oct 4, 2024

10-12B/A

Common Stock, par value $0.01 per share

Sep 13, 2024

Proxies

TYPE

HEADLINE

FILED AT

DEFA14A

Form DEFA14A - Additional definitive proxy soliciting materials and Rule 14(a)(12) material

Dec 19, 2025

DEF 14A

Form DEF 14A - Other definitive proxy statements

Dec 19, 2025

DEFA14A

Form DEFA14A - Additional definitive proxy soliciting materials and Rule 14(a)(12) material

Jan 21, 2025

DEF 14A

Form DEF 14A - Other definitive proxy statements

Jan 21, 2025

Ownerships

TYPE

HEADLINE

FILED AT

Thompson Christopher M.T. (Reporting)

Sep 17, 2026

SCHEDULE 13G

PRIMECAP MANAGEMENT CO/CA/ (Filed by)

Aug 6, 2026

Heller John E. (Reporting)

May 7, 2026

Mullen Sean Thomas (Reporting)

May 7, 2026

Johnson Travis Barton (Reporting)

May 7, 2026

Bruning Jill L (Reporting)

May 7, 2026

Other

TYPE

HEADLINE

FILED AT

EFFECT

Form EFFECT - Notice of Effectiveness

Mar 12, 2025

CORRESP

Form CORRESP - Correspondence

Mar 10, 2025

CORRESP

Form CORRESP - Correspondence

Mar 10, 2025

LETTER

Form UPLOAD - SEC-generated letter

Jan 24, 2025

ORDER

Form SEC STAFF ACTION - SEC Staff Action: ORDER

Sep 18, 2024

CORRESP

Form CORRESP - Correspondence

Sep 16, 2024

Amentum Holdings, Inc. AMTM · SEC Filings