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Amentum Holdings, Inc. (AMTM) institutional ownership

Latest close $22.55 Jul 24, 2026
Market cap$5.4B 52-week range SectorIndustrials
Funds holding · Q1 2026
422
reported AMTM position changes
Top owners · Q1 2026
No disclosed owners are available.
Institutional activity · Q1 2026
Net bought $258M
215 buyers · 207 sellers

Amentum Holdings, Inc. (AMTM) price and institutional activity

Dates

Q1 2026

$648M bought by 215 investors
Dimensional$61MPermian Investment Partners, LP$49M +213 more
$390M sold by 207 investors
Norges-$72MExoduspoint Capital Management, LP-$37M +205 more
Bought Sold Totals per quarter; hover a bar for the names.

Amentum Holdings, Inc. (AMTM) institutional activity · 422

Investor Type Est. change Change Δ Own Date
Norges · Exited −$72M
Change −2.3M Δ Own −100.0% Date Q1 2026
Norges Exited· Q1 2026 −$72M −2.3M −100.0% Q1 2026
Dimensional · Added +$61M
Change +2.0M Date Q1 2026
Dimensional Added· Q1 2026 +$61M +2.0M Q1 2026
Permian Investment Partners, LP · New +$49M
Change +1.6M Date Q1 2026
Permian Investment Partners, LP New· Q1 2026 +$49M +1.6M Q1 2026
Toronto Dominion Bank · New +$49M
Change +1.6M Date Q1 2026
Toronto Dominion Bank New· Q1 2026 +$49M +1.6M Q1 2026
UBS Group AG · Added +$47M
Change +1.5M Date Q1 2026
UBS Group AG Added· Q1 2026 +$47M +1.5M Q1 2026
Bank of America Corp · Added +$39M
Change +1.2M Date Q1 2026
Bank of America Corp Added· Q1 2026 +$39M +1.2M Q1 2026
Exoduspoint Capital Management, LP · Exited −$37M
Change −1.2M Δ Own −100.0% Date Q1 2026
Exoduspoint Capital Management, LP Exited· Q1 2026 −$37M −1.2M −100.0% Q1 2026
FMR LLC · Reduced −$35M
Change −1.1M Δ Own −16.8% Date Q1 2026
FMR LLC Reduced· Q1 2026 −$35M −1.1M −16.8% Q1 2026
Segra Capital Management, LLC · Added +$32M
Change +1.0M Date Q1 2026
Segra Capital Management, LLC Added· Q1 2026 +$32M +1.0M Q1 2026
Troluce Capital Advisors LLC · New +$31M
Change +1.0M Date Q1 2026
Troluce Capital Advisors LLC New· Q1 2026 +$31M +1.0M Q1 2026
AQR Capital Management LLC · Reduced −$30M
Change −944K Date Q1 2026
AQR Capital Management LLC Reduced· Q1 2026 −$30M −944K Q1 2026
Point72 Asset Management, L.P. · Added +$29M
Change +935K Δ Own +134.5% Date Q1 2026
Point72 Asset Management, L.P. Added· Q1 2026 +$29M +935K +134.5% Q1 2026
Mirae Asset Global Etfs Holdings Ltd. · Added +$26M
Change +823K Date Q1 2026
Mirae Asset Global Etfs Holdings Ltd. Added· Q1 2026 +$26M +823K Q1 2026
Fil Ltd · Reduced −$24M
Change −777K Date Q1 2026
Fil Ltd Reduced· Q1 2026 −$24M −777K Q1 2026
Ruane, Cunniff & Goldfarb L.P. · Reduced −$24M
Change −771K Δ Own −32.2% Date Q1 2026
Ruane, Cunniff & Goldfarb L.P. Reduced· Q1 2026 −$24M −771K −32.2% Q1 2026
Data through Q1 2026 · filed Jun 11, 2026
15 of 422

Famous investor activity in Amentum Holdings, Inc. (AMTM)

Amentum Holdings, Inc. (AMTM) insider trading

Company insiders, action and economics first; trade and filed dates last.
Dates
Insider Title Type Price Qty Value Owned ΔOwn Trade date Filed date
Heller John E. · Director 2 operations 0
Owned 18K Trade date May 6, 2026 Filed date May 7, 2026
Heller John E. Director 2 operations 0 18K May 6, 2026 May 7, 2026
Heller John E. · Director Tax withholding or exercise payment (F) -$204K
Price $24.89 Qty -8K Owned 376K Trade date May 6, 2026 Filed date May 7, 2026
Heller John E. Director Tax withholding or exercise payment (F) $24.89 -8K -$204K 376K May 6, 2026 May 7, 2026
Mullen Sean Thomas · Officer 2 operations 0
Owned 9K Trade date May 6, 2026 Filed date May 7, 2026
Mullen Sean Thomas Officer 2 operations 0 9K May 6, 2026 May 7, 2026
Mullen Sean Thomas · Officer Tax withholding or exercise payment (F) -$69K
Price $24.89 Qty -3K Owned 32K Trade date May 6, 2026 Filed date May 7, 2026
Mullen Sean Thomas Officer Tax withholding or exercise payment (F) $24.89 -3K -$69K 32K May 6, 2026 May 7, 2026
Johnson Travis Barton · CFO 2 operations 0
Owned 14K Trade date May 6, 2026 Filed date May 7, 2026
Johnson Travis Barton CFO 2 operations 0 14K May 6, 2026 May 7, 2026
Johnson Travis Barton · CFO Tax withholding or exercise payment (F) -$102K
Price $24.89 Qty -4K Owned 118K Trade date May 6, 2026 Filed date May 7, 2026
Johnson Travis Barton CFO Tax withholding or exercise payment (F) $24.89 -4K -$102K 118K May 6, 2026 May 7, 2026
Bruning Jill L. · Officer 2 operations 0
Owned 9K Trade date May 6, 2026 Filed date May 7, 2026
Bruning Jill L. Officer 2 operations 0 9K May 6, 2026 May 7, 2026
Bruning Jill L. · Officer Tax withholding or exercise payment (F) -$68K
Price $24.89 Qty -3K Owned 197K Trade date May 6, 2026 Filed date May 7, 2026
Bruning Jill L. Officer Tax withholding or exercise payment (F) $24.89 -3K -$68K 197K May 6, 2026 May 7, 2026
Arnette Stephen A. · Officer 2 operations 0
Owned 14K Trade date May 6, 2026 Filed date May 7, 2026
Arnette Stephen A. Officer 2 operations 0 14K May 6, 2026 May 7, 2026
Arnette Stephen A. · Officer Tax withholding or exercise payment (F) -$82K
Price $24.89 Qty -3K Owned 107K Trade date May 6, 2026 Filed date May 7, 2026
Arnette Stephen A. Officer Tax withholding or exercise payment (F) $24.89 -3K -$82K 107K May 6, 2026 May 7, 2026
Bruning Jill L. · Officer Gift (G) -30K
Owned 191K Trade date Mar 4, 2026 Filed date Mar 5, 2026
Bruning Jill L. Officer Gift (G) -30K 191K Mar 4, 2026 Mar 5, 2026
Arnette Stephen A. · Officer 2 operations 0
Owned 0 Trade date Mar 2, 2026 Filed date Mar 4, 2026
Arnette Stephen A. Officer 2 operations 0 0 Mar 2, 2026 Mar 4, 2026
Arnette Stephen A. · Officer Tax withholding or exercise payment (F) -$23K
Price $30.70 Qty -750 Owned 96K Trade date Mar 2, 2026 Filed date Mar 4, 2026
Arnette Stephen A. Officer Tax withholding or exercise payment (F) $30.70 -750 -$23K 96K Mar 2, 2026 Mar 4, 2026
St. Mary Michele T. · Officer 2 operations 0
Owned 14K Trade date Feb 17, 2026 Filed date Feb 18, 2026
St. Mary Michele T. Officer 2 operations 0 14K Feb 17, 2026 Feb 18, 2026
St. Mary Michele T. · Officer Tax withholding or exercise payment (F) -$69K
Price $30.05 Qty -2K Owned 27K Trade date Feb 17, 2026 Filed date Feb 18, 2026
St. Mary Michele T. Officer Tax withholding or exercise payment (F) $30.05 -2K -$69K 27K Feb 17, 2026 Feb 18, 2026
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Amentum Holdings, Inc. (AMTM) activist and large shareholders

Dates
Owner/Filer identity Shares reported % of shares outstanding Filing date
Amentum Joint Venture LP 90.0M
% of shares outstanding 37.0% Filing date Oct 4, 2024
Amentum Joint Venture LP 90.0M 37.0% Oct 4, 2024
Invesco Ltd. 24.5M
% of shares outstanding 10.1% Filing date May 7, 2026
Invesco Ltd. 24.5M 10.1% May 7, 2026
Vanguard Group Inc 14.0M
% of shares outstanding 9.1% Filing date Nov 12, 2024
Vanguard Group Inc 14.0M 9.1% Nov 12, 2024
Jacobs Solutions Inc. 18.2M
% of shares outstanding 7.5% Filing date Nov 12, 2024
Jacobs Solutions Inc. 18.2M 7.5% Nov 12, 2024
Blackrock, Inc. 8.9M
% of shares outstanding 5.8% Filing date Nov 12, 2024
Blackrock, Inc. 8.9M 5.8% Nov 12, 2024
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Amentum Holdings, Inc. (AMTM) ownership FAQ

Who owns AMTM?

422 reporting institutions disclosed AMTM position changes in the Q1 2026 snapshot.

How is institutional activity calculated?

For each manager, WhoBought compares accepted consecutive 13F share counts. Share change is current shares minus prior shares. Estimated dollar change is that signed share change multiplied by the split-adjusted quarter-mean close. The activity table on this page uses Q1 2026.

What are activist and large shareholder filings?

An investor crossing 5% of a share class generally files Schedule 13D for activist intent or Schedule 13G for a passive position. The technical form names appear here rather than in the activity rows.

Where does this data come from?

Ownership and institutional activity come from SEC Form 13F filings. Insider activity comes from SEC Form 4, and large-shareholder activity from SEC Schedules 13D and 13G. FMP supplies price data only. Company logos use the local verified Parqet cache with one shared fallback.

Why are ownership reports delayed?

Form 13F is a quarterly disclosure and is normally filed after the quarter ends. Every ownership and activity value therefore names its represented period; it is not presented as a live position.

How are missing table values shown?

A muted dash marks a missing table value. It means the filing omitted the value, comparable data is unavailable, or no prior position exists for comparison.