Companies / Amentum Holdings, Inc.

Amentum Holdings, Inc.

NYSE: AMTMCIK 2011286CHANTILLY, VA

Financials · FY2025

Revenue$14.39B
Net income$66.00M
Total debt$3.83B
Cash$459.00M
Diluted EPS$0.27
Shares outstanding244.5M

Ownership

244.5M shares outstanding · as of Aug 7, 2026
0.50%Insiders
Ownership
Insiders0.50%1,229,187
Institutions83.73%204,731,269
Public float15.76%38,545,957

% of common shares outstanding (exact, from the latest cover-page filing). Institutions are quarterly 13F snapshots; insiders reflect current officers & directors.

Insiders 12

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Insider% of sharesShares
Vollmer John C.Director
0.18%429,842
Heller John E.CEOChief Executive Officer · Director
0.15%366,058
Bruning Jill LChief Technology Officer
0.08%190,999
Arnette Stephen AChief Operating Officer
0.04%96,357
Eberhart Ralph EDirector
0.02%48,120
Brooks Vincent KDirector
0.01%27,462
St. Mary Michele TChief Legal Officer & GC
0.01%27,043
Rowland Sandra E.Director
<0.01%20,073
Loughran BarbaraDirector
<0.01%9,662
Ireland Susan LeslieDirector
<0.01%8,509

Institutional holders 489

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HolderValue% of shares
American Securities LLC$1.31B18.42%
Invesco Ltd.$633.19M8.93%
Vanguard Group Inc$446.94M6.30%
BlackRock, Inc.$370.14M7.32%
Primecap Management CO/CA$351.68M4.96%
Fmr LLC$194.51M2.74%
Frontier Capital Management CO.,LLC$167.42M2.36%
State Street Corporation$106.49M2.11%
Focus Partners Wealth$81.04M1.14%
Geode Capital Management, LLC$73.42M1.15%

Activity

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InsidersInstitutions
What insiders are doing in this stock (Form 4).
DateActorActionSecurityValueShares ΔPosition afterImpact
Jan 28, 2026Heller John E.
CEO
OtherCommon Stock$705.9K-20K
-5.12%
366,058
0.15% of shares
low
Feb 17, 2026St. Mary Michele T
Executive
OtherCommon Stock$69.4K-2K
-7.86%
27,043
0.01% of shares
low
Mar 2, 2026Arnette Stephen A
Executive
OtherCommon Stock$23.0K-750
-0.77%
96,357
0.04% of shares
low
Mar 4, 2026Bruning Jill L
Executive
GiftCommon Stock$0-30K
-13.57%
190,999
0.08% of shares
low
Feb 6, 2026Brooks Vincent K
Director
GrantCommon Stock$0+5K
+22.60%
27,462
0.01% of shares
low
Feb 6, 2026Loughran Barbara
Director
GrantCommon Stock$0+5K
+110.04%
9,662
<0.01% of shares
low
Feb 6, 2026Vollmer John C.
Director
GrantCommon Stock$0+5K
+1.19%
429,842
0.18% of shares
low
Feb 6, 2026Ireland Susan Leslie
Director
GrantCommon Stock$0+5K
+146.85%
8,509
<0.01% of shares
low

5%+ ownership events

Schedule 13D / 13G
FilerStance% of classSharesDate
Vanguard Group IncPassive13G/A—0—

Securities

via CUSIP / OpenFIGI
SymbolTypeMarketCUSIPFIGI
AMTM——023939101—