Who owns Amentum Holdings, Inc.?
Prices and market caps: Cboe delayed data, at least 15 minutes delayed. Not real-time. Fundamentals from company filings.
Institutional ownership of AMTM from SEC Form 13F filings across 463 reporting managers. All positions are from one synchronized reporting period — 2026-06-30 books, filed up to 45 days after quarter end — so every row is comparable.
As of the 2026-06-30 reporting period, 463 institutions disclosed 218.9M shares of Amentum Holdings, Inc. worth $4.34B — about 89.7% of shares outstanding; the largest disclosed holder is AMERICAN SECURITIES LLC. Source: SEC Form 13F filings, parsed by EvidInvest.
463
13F holders
$4.34B
value, 2026 filers
89.7%
of shares outstanding (218.9M sh)
65
new positions (2026 filers)
Top institutional holders
ordered by shares owned · positions as of 2026-06-30 · % of fund = share of the manager's own book · % of co. = share of AMTM's shares outstanding
| # | Manager | Shares | Value | % of fund | % of co. | Δ shares QoQ |
|---|---|---|---|---|---|---|
| 1 | AMERICAN SECURITIES LLC | 45.0M | $930.7M | 24.8% | 18.5% | 0.0% |
| 2 | Invesco Ltd. | 25.0M | $515.8M | 0.0% | 10.2% | +16.2% |
| 3 | BlackRock, Inc. | 17.9M | $370.1M | 0.0% | 7.3% | +0.4% |
| 4 | PRIMECAP MANAGEMENT CO/CA/ | 12.3M | $253.9M | 0.2% | 5% | +1.7% |
| 5 | Legacy Advisors, LLC | 9.1M | $9.1M | 0.8% | 3.7% | 0.0% |
| 6 | VANGUARD PORTFOLIO MANAGEMENT LLC | 7.9M | $164.3M | 0.0% | 3.3% | +1.2% |
| 7 | VANGUARD CAPITAL MANAGEMENT LLC | 6.7M | $138.7M | 0.0% | 2.8% | +0.9% |
| 8 | FMR LLC | 5.7M | $117.4M | 0.0% | 2.3% | +1.8% |
| 9 | DIMENSIONAL FUND ADVISORS LP | 5.5M | $114.5M | 0.0% | 2.3% | +46.2% |
| 10 | STATE STREET CORP | 5.2M | $106.5M | 0.0% | 2.1% | +1.4% |
| 11 | FRONTIER CAPITAL MANAGEMENT CO LLC | 4.1M | $85.7M | 0.8% | 1.7% | -15.9% |
| 12 | Troluce Capital Advisors LLC | 3.6M | $73.7M | 7.6% | 1.5% | +256.5% |
| 13 | GEODE CAPITAL MANAGEMENT, LLC | 2.7M | $56.2M | 0.0% | 1.1% | -3.5% |
| 14 | GOLDMAN SACHS GROUP INC | 2.7M | $56.1M | 0.0% | 1.1% | +139.7% |
| 15 | MORGAN STANLEY | 2.7M | $55.0M | 0.0% | 1.1% | +19.1% |
| 16 | MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. | 2.3M | $47.9M | 0.1% | 1% | -16.8% |
| 17 | THOMPSON SIEGEL & WALMSLEY LLC | 2.3M | $47.2M | 0.8% | 0.9% | +49.5% |
| 18 | MILLENNIUM MANAGEMENT LLC | 2.1M | $44.0M | 0.0% | 0.9% | +237.2% |
| 19 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 2.1M | $43.8M | 0.0% | 0.9% | +2.5% |
| 20 | Thrivent Financial for Lutherans | 2.1M | $43.5M | 0.1% | 0.9% | +0.3% |
| 21 | BANK OF AMERICA CORP /DE/ | 2.0M | $42.2M | 0.0% | 0.8% | -15.1% |
| 22 | SEGRA CAPITAL MANAGEMENT, LLC | 2.0M | $42.1M | 8.5% | 0.8% | +26.4% |
| 23 | Verition Fund Management LLC | 2.0M | $41.7M | 0.2% | 0.8% | +55.6% |
| 24 | VAN ECK ASSOCIATES CORP | 2.0M | $41.1M | 0.0% | 0.8% | +263.2% |
| 25 | VOYA INVESTMENT MANAGEMENT LLC | 2.0M | $40.8M | 0.0% | 0.8% | +64.6% |
Source: SEC Form 13F-HR filings (institutional managers over $100M in US-listed positions). 13Fs disclose long positions only, up to 45 days after quarter end; each manager's latest filed quarter is shown per row and dollar values are the manager's filed marks. Aggregates labeled "2026 filers" count only managers whose latest book is a 2026 quarter. Related: valuation · options positioning · supply chain. Research, not investment advice.