13F Insight
DOSSIER · 13F Holders · Q1 2026Technology · Services-Business Services, NECCyclicalNet sold
AMTM

AMENTUM HOLDINGS INC

515 institutions still hold AMENTUM HOLDINGS INC as of Q1 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 023939101·Services-Business Services, NEC·515 13F holders·last filed Mar 31, 2026
Market cap
—
▲ 5.0%
vs prior quarter
13F value held
$4.0B
79.0% inst. owned
of float
Holders
515
+4 QoQ
filers reporting
Activity
+78 / −12
+716 added · −639 reduced
this quarter
Concentration
29.10%
AMERICAN SECURITIES LLC #1
top holder share
AI Holders Summary · Q1 2026

515 institutions reported AMTM in Q1 2026. AMERICAN SECURITIES LLC leads at 29.1% of the visible book. +4 net new institutions vs prior quarter — accumulation reading.

Top holders

Sorted by position value. Source: SEC EDGAR 13F-HR filings.

#HolderValueShares% port.Quarter
01
AMERICAN SECURITIES LLC
CIK 0001475483
$1.2B45.0M29.88%Q1 202602
Invesco Ltd.
CIK 0000914208
$560M21.5M0.09%Q1 202603
BlackRock, Inc.
CIK 0002012383
$465M17.8M0.01%Q1 202604
PRIMECAP MANAGEMENT CO/CA/
CIK 0000763212
$315M12.1M0.25%Q1 202605
Vanguard Portfolio Management
CIK 0002100121
$205M7.9M0.01%Q1 202606
VANGUARD CAPITAL MANAGEMENT LLC
CIK 0002100119· Index
$173M6.7M0.00%Q1 202607
FMR LLC
CIK 0000315066
$145M5.6M0.01%Q1 202608
STATE STREET CORP
CIK 0000093751
$132M5.1M0.00%Q1 202609
FRONTIER CAPITAL MANAGEMENT CO LLC
CIK 0000351173
$129M4.9M1.32%Q1 202610
DIMENSIONAL FUND ADVISORS LP
CIK 0000354204· Quasi-passive
$99M3.8M0.02%Q1 202611
Focus Partners Wealth
CIK 0001542153
$81M2.8M0.09%Q4 202512
Arvin Capital Management LP
CIK 0001961738
$73M2.8M8.97%Q1 202613
GEODE CAPITAL MANAGEMENT, LLC
CIK 0001214717· Index
$73M2.8M0.00%Q1 202614
MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd.
CIK 0001705339
$73M2.8M0.10%Q1 202615
Ruane, Cunniff & Goldfarb L.P.
CIK 0001720792
$69M2.4M1.08%Q4 202516
BANK OF AMERICA CORP /DE/
CIK 0000070858
$63M2.4M0.00%Q1 202617
MORGAN STANLEY
CIK 0000895421
$58M2.2M0.00%Q1 202618
CHARLES SCHWAB INVESTMENT MANAGEMENT INC
CIK 0000884546· Index
$54M2.1M0.01%Q1 202619
SEGRA CAPITAL MANAGEMENT, LLC
CIK 0001607512
$47M1.8M19.06%Q1 202620
UBS Group AG
CIK 0001610520
$45M1.7M0.01%Q1 2026
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