Who owns AMTM?
Institutional ownership of Amentum Holdings Inc. from Form 13F, Q2 2026
460 institutional managers reported holding Amentum Holdings Inc. (AMTM) in Form 13F filings for Q2 2026, with 219,070,004 shares worth $4.5B. The largest reported holder was American Securities LLC. Managers that filed both quarters added a net 8,099,046 shares (+3.8%). 53 opened new positions and 75 sold out.
- Funds holding
- 460
- Value held
- $4.5B
- New / sold out
- 53 / 75
- Net shares, same filers
- +3.8%
Holdings as of June 30, 2026, the end of Q2 2026. Managers have 45 days after a quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.
Largest holders of AMTM
| Fund | Value | Share of 13F holdings | Shares | Move |
|---|---|---|---|---|
| American Securities LLC | $931M | 20.6% | 45,026,743 | Unchanged |
| Invesco Ltd. | $516M | 11.4% | 24,954,251 | Added |
| BlackRock, Inc. | $370M | 8.2% | 17,906,984 | Added |
| Primecap Management Co | $254M | 5.6% | 12,285,504 | Added |
| Legacy Advisors, LLC | $187M | 4.1% | 9,065,677 | Unchanged |
| Vanguard Portfolio Management LLC | $164M | 3.6% | 7,948,385 | Added |
| Vanguard Capital Management LLC | $139M | 3.1% | 6,711,987 | Added |
| FMR LLC | $117M | 2.6% | 5,679,175 | Added |
| Dimensional Fund Advisors LP | $114M | 2.5% | 5,537,696 | Added |
| State Street Corp | $106M | 2.4% | 5,151,772 | Added |
| Frontier Capital Management Co LLC | $85.7M | 1.9% | 4,143,971 | Trimmed |
| Troluce Capital Advisors LLC | $73.7M | 1.6% | 3,565,399 | Added |
| Geode Capital Management, LLC | $56.2M | 1.2% | 2,716,560 | Trimmed |
| Goldman Sachs Group Inc | $56.1M | 1.2% | 2,711,866 | Added |
| Morgan Stanley | $55.0M | 1.2% | 2,662,329 | Added |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. | $47.9M | 1.1% | 2,318,581 | Trimmed |
| Thompson Siegel & Walmsley LLC | $47.2M | 1.0% | 2,281,945 | Added |
| Millennium Management LLC | $44.0M | 1.0% | 2,127,779 | Added |
| Charles Schwab Investment Management Inc | $43.8M | 1.0% | 2,120,102 | Added |
| Thrivent Financial for Lutherans | $43.5M | 1.0% | 2,105,802 | Added |
| Bank of America Corp | $42.2M | 0.9% | 2,042,897 | Trimmed |
| Segra Capital Management, LLC | $42.1M | 0.9% | 2,037,890 | Added |
| Verition Fund Management LLC | $41.7M | 0.9% | 2,019,334 | Added |
| Van Eck Associates Corp | $41.1M | 0.9% | 1,988,898 | Added |
| Voya Investment Management LLC | $40.8M | 0.9% | 1,974,191 | Added |
Share of 13F holdings is each fund's shares as a share of the 219,070,004 AMTM shares all 13F filers reported, not of shares outstanding.
Biggest buyers in Q2 2026
- Invesco Ltd. Added+$71.9M
- Troluce Capital Advisors LLC Added+$53.0M
- Dimensional Fund Advisors LP Added+$36.2M
- Goldman Sachs Group Inc Added+$32.7M
- Norges Bank New+$31.3M
- Millennium Management LLC Added+$30.9M
- Van Eck Associates Corp Added+$29.8M
- Qube Research & Technologies Ltd Added+$19.8M
- Voya Investment Management LLC Added+$16.0M
- Thompson Siegel & Walmsley LLC Added+$15.6M
Biggest sellers in Q2 2026
- Focus Partners Wealth Trimmed-$51.0M
- Toronto Dominion Bank Sold out-$40.8M
- Brightline Capital Management, LLC Sold out-$36.4M
- Arvin Capital Management LP Trimmed-$34.2M
- Cooper Creek Partners Management LLC Sold out-$24.2M
- Ruane, Cunniff & Goldfarb L.P. Trimmed-$22.4M
- Point72 Asset Management, L.P. Trimmed-$20.3M
- Penn Capital Management Company, LLC Sold out-$18.2M
- Frontier Capital Management Co LLC Trimmed-$16.3M
- FIL Ltd Trimmed-$13.5M
The change in shares since the quarter before, adjusted for stock splits and priced at the Q2 2026 value per share. Funds bought $544M and sold $410M; 146 added and 155 trimmed.
Schedule 13D and 13G filings on AMTM
Owners of more than 5% must file within days, so these can be newer than the 13F data.
- 2026-08-06PRIMECAP MANAGEMENT CO/CA/ SCHEDULE 13G filed by Amentum Holdings Inc.Schedule 13G
- 2025-02-07Invesco Ltd. SCHEDULE 13G filed by Amentum Holdings Inc.Schedule 13G
Questions about AMTM ownership
- Who owns AMTM stock?
- 460 institutional investment managers reported AMTM positions in their Form 13F filings for Q2 2026, holding 219,070,004 shares worth $4.5B in total. American Securities LLC reported the largest position.
- Are funds buying or selling AMTM?
- In Q2 2026, 53 managers opened new AMTM positions, 146 added, 155 trimmed and 75 sold out. Managers that filed in both quarters added a net 8,099,046 shares.
- How current is this AMTM institutional ownership data?
- It covers holdings as of the end of Q2 2026. Managers have 45 days after the quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.
From the SEC's Form 13F data sets for Q2 2026: every 13F holdings report, matched to AMTM by CUSIP. Options are left out. AMTM news and filings · AMTM insider trades · Top funds