AMTM Amentum Holdings, Inc.
Amentum Holdings, Inc. (AMTM) Institutional Ownership
What the institutions did with AMTM last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.
Every manager below opens. Subscribers can see any firm's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.
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Each block is one manager, sized by shares held and colored by how much they moved the position last quarter. Green added, red cut, grey stood pat.
Largest holders
| Manager | Shares | % of reported |
|---|---|---|
| AMERICAN SECURITIES LLC | 45.0M | 20.6% |
| Invesco Ltd. | 25.0M | 11.4% |
| BlackRock, Inc. | 17.9M | 8.2% |
| PRIMECAP MANAGEMENT CO/CA/ | 12.3M | 5.6% |
| Legacy Advisors, LLC | 9.1M | 4.1% |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 7.9M | 3.6% |
| VANGUARD CAPITAL MANAGEMENT LLC | 6.7M | 3.1% |
| FMR LLC | 5.7M | 2.6% |
| DIMENSIONAL FUND ADVISORS LP | 5.5M | 2.5% |
| STATE STREET CORP | 5.2M | 2.4% |
| FRONTIER CAPITAL MANAGEMENT CO LLC | 4.1M | 1.9% |
| Troluce Capital Advisors LLC | 3.6M | 1.6% |
| GEODE CAPITAL MANAGEMENT, LLC | 2.7M | 1.2% |
| GOLDMAN SACHS GROUP INC | 2.7M | 1.2% |
| MORGAN STANLEY | 2.7M | 1.2% |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. | 2.3M | 1.1% |
| THOMPSON SIEGEL & WALMSLEY LLC | 2.3M | 1.0% |
| MILLENNIUM MANAGEMENT LLC | 2.1M | 1.0% |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 2.1M | 1.0% |
| Thrivent Financial for Lutherans | 2.1M | 1.0% |
| BANK OF AMERICA CORP /DE/ | 2.0M | 0.9% |
| SEGRA CAPITAL MANAGEMENT, LLC | 2.0M | 0.9% |
| Verition Fund Management LLC | 2.0M | 0.9% |
| VAN ECK ASSOCIATES CORP | 2.0M | 0.9% |
| VOYA INVESTMENT MANAGEMENT LLC | 2.0M | 0.9% |
Largest changes
| Manager | Action | Previous | Current | Change |
|---|---|---|---|---|
| Invesco Ltd. | Increased | 21.5M | 25.0M | +3.5M |
| Troluce Capital Advisors LLC | Increased | 1.0M | 3.6M | +2.6M |
| Focus Partners Wealth | Reduced | 2.6M | 138.3K | -2.5M |
| DIMENSIONAL FUND ADVISORS LP | Increased | 3.8M | 5.5M | +1.8M |
| Arvin Capital Management LP | Reduced | 2.1M | 416.7K | -1.7M |
| GOLDMAN SACHS GROUP INC | Increased | 1.1M | 2.7M | +1.6M |
| TORONTO DOMINION BANK | Sold Out | 1.6M | 0 | -1.6M |
| MILLENNIUM MANAGEMENT LLC | Increased | 631.1K | 2.1M | +1.5M |
| VAN ECK ASSOCIATES CORP | Increased | 547.6K | 2.0M | +1.4M |
| BRIGHTLINE CAPITAL MANAGEMENT, LLC | Sold Out | 1.4M | 0 | -1.4M |
| Ruane, Cunniff & Goldfarb L.P. | Reduced | 1.6M | 537.2K | -1.1M |
| Point72 Asset Management, L.P. | Reduced | 1.6M | 650.0K | -980.6K |
| Qube Research & Technologies Ltd | Increased | 77.4K | 1.0M | +957.0K |
| COOPER CREEK PARTNERS MANAGEMENT LLC | Sold Out | 929.3K | 0 | -929.3K |
| FRONTIER CAPITAL MANAGEMENT CO LLC | Reduced | 4.9M | 4.1M | -786.2K |
| VOYA INVESTMENT MANAGEMENT LLC | Increased | 1.2M | 2.0M | +774.7K |
| THOMPSON SIEGEL & WALMSLEY LLC | Increased | 1.5M | 2.3M | +756.1K |
| Verition Fund Management LLC | Increased | 1.3M | 2.0M | +721.4K |
| Penn Capital Management Company, LLC | Sold Out | 694.4K | 0 | -694.4K |
| HRT FINANCIAL LP | New | 0 | 671.8K | +671.8K |
| FIL Ltd | Reduced | 652.2K | 1.4K | -650.8K |
| TWO SIGMA INVESTMENTS, LP | Reduced | 900.2K | 284.3K | -615.9K |
| CITADEL ADVISORS LLC | Increased | 80.6K | 670.7K | +590.0K |
| MOORE CAPITAL MANAGEMENT, LP | Reduced | 873.6K | 365.1K | -508.5K |
| Loews Corp | New | 0 | 500.0K | +500.0K |
| SHAPIRO CAPITAL MANAGEMENT LLC | New | 0 | 476.0K | +476.0K |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. | Reduced | 2.8M | 2.3M | -466.6K |
| Nuveen, LLC | Reduced | 871.8K | 421.5K | -450.3K |
| MORGAN STANLEY | Increased | 2.2M | 2.7M | +427.4K |
| NEW YORK STATE COMMON RETIREMENT FUND | Reduced | 502.5K | 75.2K | -427.3K |
| SEGRA CAPITAL MANAGEMENT, LLC | Increased | 1.6M | 2.0M | +425.2K |
| CI INVESTMENTS INC. | Sold Out | 420.1K | 0 | -420.1K |
| Gotham Asset Management, LLC | Reduced | 521.0K | 156.1K | -364.9K |
| BANK OF AMERICA CORP /DE/ | Reduced | 2.4M | 2.0M | -362.1K |
| 683 Capital Management, LLC | Increased | 775.0K | 1.1M | +325.0K |
| FIRST TRUST ADVISORS LP | Increased | 228.1K | 547.9K | +319.8K |
| Hyperion Capital Advisors LP | Sold Out | 303.6K | 0 | -303.6K |
| BOOTHBAY FUND MANAGEMENT, LLC | Increased | 86.2K | 388.0K | +301.8K |
| AWH Capital, L.P. | Increased | 235.3K | 470.5K | +235.3K |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE | Increased | 40.9K | 273.6K | +232.7K |
| FIRST NATIONAL BANK OF OMAHA | Increased | 248.0K | 476.0K | +228.0K |
| ExodusPoint Capital Management, LP | New | 0 | 226.3K | +226.3K |
| PRIMECAP MANAGEMENT CO/CA/ | Increased | 12.1M | 12.3M | +200.2K |
| Verbena Value LP | New | 0 | 186.2K | +186.2K |
| CenterBook Partners LP | Increased | 143.7K | 328.8K | +185.1K |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC | Increased | 217.8K | 394.4K | +176.6K |
| UBS Group AG | Reduced | 1.7M | 1.5M | -165.6K |
| CSM Advisors, LLC | Increased | 81.2K | 243.8K | +162.6K |
| JANE STREET GROUP, LLC | Increased | 192.0K | 343.7K | +151.7K |
| ROYCE & ASSOCIATES LP | Increased | 549.8K | 697.4K | +147.6K |
| ROYAL BANK OF CANADA | Reduced | 231.7K | 92.0K | -139.7K |
| Atom Investors LP | Increased | 22.8K | 160.9K | +138.1K |
| Permian Investment Partners, LP | Reduced | 1.6M | 1.4M | -134.0K |
| Russell Investments Group, Ltd. | Increased | 713.8K | 840.6K | +126.8K |
| D. E. Shaw & Co., Inc. | Increased | 66.2K | 191.5K | +125.3K |
| WELLS FARGO & COMPANY/MN | Increased | 636.7K | 750.2K | +113.5K |
| BARCLAYS PLC | Increased | 46.8K | 151.8K | +105.0K |
| SEI INVESTMENTS CO | Reduced | 294.7K | 190.1K | -104.6K |
| FMR LLC | Increased | 5.6M | 5.7M | +100.8K |
| TWINBEECH CAPITAL LP | New | 0 | 99.7K | +99.7K |
13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.