Amentum Holdings Inc. (AMTM)
Industrials
Specialty Business Services
22.20 $
+2.2%
vs. previous close
Closing price · As of: 31. Jul 2026
Who owns Amentum Holdings Inc. (AMTM)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 62.4% of the shares are freely tradable; institutional investors hold 107.7%.
Ownership Structure
Institutional ownership
Share of the stock held by institutional investors (funds, banks, insurers) according to regulatory filings.
107.7%
Insiders
Share of the stock held by the executives, founders and major shareholders of the company itself.
1.2%
Float
Share of stock freely tradable on the market — not locked up in the hands of founders, insiders, or major shareholders.
62.4%
Short % of float
Shares sold short as a percentage of the freely tradable float — high values signal many bets on falling prices.
8.8%
Shares Outstanding
Total number of shares issued. Price times share count gives market cap.
244Mio.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| AMERICAN SECURITIES LLC | 18.43 | 45,026,743 | +0.0 | 03/31/2026 |
| Amvescap Plc. | 8.79 | 21,473,778 | -1.6 | 03/31/2026 |
| BlackRock Inc | 7.30 | 17,841,283 | +2.2 | 03/31/2026 |
| PRIMECAP Management Company | 4.95 | 12,085,294 | -0.3 | 03/31/2026 |
| Legacy Advisors, LLC | 3.71 | 9,065,677 | +0.0 | 06/30/2026 |
| Vanguard Portfolio Management, LLC | 3.21 | 7,852,951 | +0.0 | 03/31/2026 |
| Vanguard Capital Management, LLC | 2.72 | 6,650,879 | +0.0 | 03/31/2026 |
| FMR Inc | 2.28 | 5,578,386 | -16.8 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| iShares Core S&P Small-Cap ETF | 3.84 | 9,391,310 | +0.0 | 07/28/2026 |
| Vanguard PRIMECAP Core Inv | 2.16 | 5,270,119 | +0.0 | 03/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Data as of: July 31, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.