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Amentum Holdings, Inc.

AMTM
Exchange
NYSE
Industry
Services-Business Services, NEC
SEC CIK
0002011286

No open-market purchases or sales by Amentum Holdings, Inc. insiders were filed in the last 90 days; 464 institutions reported holding it in 13F filings for Q2 2026, worth $4.35B in total; Soros Fund Management is the only superinvestor holding it.

13F holders, Q1 2026

Institutional positions in Amentum Holdings, Inc. as of Mar 31, 2026. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works

Institutional holders
486
+10 vs. Q4 2025
Shares held
211.1M
+25.3M (+13.6%) vs. Q4 2025
Total value
$5.28B
+$162.1M (+3.2%) vs. Q4 2025
New holders
70
151 more added
Sold out
60
152 more reduced

7 institutions that held it in Q4 2025 haven't filed for Q1 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q4 2025: new holders, sold out and not filed yet

Holders and value by quarter

Institutions reporting AMTM on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.

Institutional holdersQ1 2026: 486 institutions
Q1 2021: 0 institutionsQ2 2021: 0 institutionsQ3 2021: 0 institutionsQ4 2021: 0 institutionsQ1 2022: 0 institutionsQ2 2022: 0 institutionsQ3 2022: 0 institutionsQ4 2022: 0 institutionsQ1 2023: 0 institutionsQ2 2023: 0 institutionsQ3 2023: 0 institutionsQ4 2023: 0 institutionsQ1 2024: 0 institutionsQ2 2024: 0 institutionsQ3 2024: 492 institutionsQ4 2024: 451 institutionsQ1 2025: 418 institutionsQ2 2025: 461 institutionsQ3 2025: 462 institutionsQ4 2025: 483 institutionsQ1 2026: 486 institutionsQ2 2026: 464 institutions
Value heldQ1 2026: $5.28B
Q1 2021: $0Q2 2021: $0Q3 2021: $0Q4 2021: $0Q1 2022: $0Q2 2022: $0Q3 2022: $0Q4 2022: $0Q1 2023: $0Q2 2023: $0Q3 2023: $0Q4 2023: $0Q1 2024: $0Q2 2024: $0Q3 2024: $3.25BQ4 2024: $3.50BQ1 2025: $3.50BQ2 2025: $4.74BQ3 2025: $4.63BQ4 2025: $5.64BQ1 2026: $5.28BQ2 2026: $4.35B
Institutions holding AMTM and their total value by quarter
QuarterHoldersValue
Q2 2026464$4.35B
Q1 2026486$5.28B
Q4 2025483$5.64B
Q3 2025462$4.63B
Q2 2025461$4.74B
Q1 2025418$3.50B
Q4 2024451$3.50B
Q3 2024492$3.25B
Q2 20240$0
Q1 20240$0
Q4 20230$0
Q3 20230$0
Q2 20230$0
Q1 20230$0
Q4 20220$0
Q3 20220$0
Q2 20220$0
Q1 20220$0
Q4 20210$0
Q3 20210$0
Q2 20210$0
Q1 20210$0

Institutions, Q1 2026

Shares, value and share of portfolio for each institution holding Amentum Holdings, Inc.; share changes are against Q4 2025.

Institutions holding AMTM in Q1 2026
InstitutionSharesValue% of portfolioChange in sharesAction
American Securities LLC45,026,743$1.17B29.88%00.0%Unchanged
Invesco Ltd.21,473,778$560.0M0.05%−360,225−1.6%Reduced
BlackRock, Inc.17,841,283$465.3M0.01%+382,184+2.2%Added
Primecap Management Co12,085,294$315.2M0.25%−41,633−0.3%Reduced
Vanguard Portfolio Management LLC7,852,951$204.8M0.01%+7,852,951New
Vanguard Capital Management LLC6,650,879$173.5M0.00%+6,650,879New
FMR LLC5,578,386$145.5M0.01%−1,128,918−16.8%Reduced
State Street Corp5,079,041$132.5M0.00%+17,421+0.3%Added
Frontier Capital Management Co LLC4,930,210$128.6M1.32%−842,766−14.6%Reduced
Dimensional Fund Advisors LP3,787,420$98.8M0.02%+1,954,494+106.6%Added
Geode Capital Management, LLC2,814,415$73.4M0.00%+155,051+5.8%Added
Mirae Asset Global ETFs Holdings Ltd.2,785,134$72.6M0.10%+823,207+42.0%Added
Colony Group, LLC2,604,911$67.9M0.08%−189,506−6.8%Reduced
Bank of America Corp2,405,041$62.7M0.00%+1,247,614+107.8%Added
Morgan Stanley2,234,913$58.3M0.00%+159,561+7.7%Added
Thrivent Financial for Lutherans2,100,457$54.8M0.10%+31,353+1.5%Added
Arvin Capital Management LP2,071,200$54.0M12.62%+434,708+26.6%Added
Charles Schwab Investment Management Inc2,067,930$53.9M0.01%+115,928+5.9%Added
UBS Group AG1,710,775$44.6M0.01%+1,504,673+730.1%Added
Point72 Asset Management, L.P.1,630,563$42.5M0.07%+935,276+134.5%Added
Ruane, Cunniff & Goldfarb L.P.1,622,982$42.3M0.70%−771,147−32.2%Reduced
Segra Capital Management, LLC1,612,726$42.1M32.74%+1,007,916+166.7%Added
Permian Investment Partners, LP1,567,000$40.9M4.52%+1,567,000New
Toronto Dominion Bank1,565,223$40.8M0.08%+1,565,223New
Thompson Siegel & Walmsley LLC1,525,884$39.8M0.70%−395,925−20.6%Reduced
Brightline Capital Management, LLC1,396,000$36.4M10.77%+4,000+0.3%Added
Verition Fund Management LLC1,297,946$33.9M0.33%+432,774+50.0%Added
Voya Investment Management LLC1,199,491$31.3M0.03%+52,014+4.5%Added
Goldman Sachs Group Inc1,131,438$29.5M0.00%+487,280+75.6%Added
Loomis Sayles & Co L P1,081,336$28.2M0.04%−37,594−3.4%Reduced
Troluce Capital Advisors LLC1,000,000$26.1M2.76%+1,000,000New
Northern Trust Corp984,105$25.7M0.00%+31,128+3.3%Added
Vanguard Fiduciary Trust Co947,460$24.7M0.01%+947,460New
Cooper Creek Partners Management LLC929,334$24.2M1.17%−623,740−40.2%Reduced
Bank of New York Mellon Corp908,599$23.7M0.00%−13,498−1.5%Reduced
Two Sigma Investments, LP900,177$23.5M0.02%+262,191+41.1%Added
Cacti Asset Management LLC881,692$23.0M1.39%00.0%Unchanged
Moore Capital Management, LP873,610$22.8M0.83%+398,296+83.8%Added
Nuveen, LLC871,795$22.7M0.01%+58,021+7.1%Added
Avenir Corp841,099$21.9M2.67%−9,845−1.2%Reduced
683 Capital Management, LLC775,000$20.2M1.87%−60,000−7.2%Reduced
Principal Financial Group Inc744,728$19.4M0.01%+16,314+2.2%Added
Russell Investments Group, Ltd.713,828$18.6M0.02%+276,812+63.3%Added
Ancora Advisors, LLC703,119$18.3M0.39%+300,773+74.8%Added
Penn Capital Management Co Inc694,352$18.2M1.41%−49,585−6.7%Reduced
FIL Ltd652,159$17.0M0.01%−777,225−54.4%Reduced
Wells Fargo & Company636,674$16.6M0.00%+171,935+37.0%Added
Millennium Management LLC631,055$16.5M0.01%+569,868+931.4%Added
Public Sector Pension Investment Board549,797$14.3M0.04%+19,231+3.6%Added
Royce & Associates LP549,778$14.3M0.14%+54,492+11.0%Added
Van Eck Associates Corp547,644$14.3M0.01%+16,637+3.1%Added
Gotham Asset Management, LLC521,041$13.6M0.04%−114,389−18.0%Reduced
AQR Capital Management LLC507,843$13.2M0.01%−944,206−65.0%Reduced
New York State Common Retirement Fund502,487$13.1M0.02%−32,731−6.1%Reduced
Ci Investments Inc.420,068$11.0M0.05%−5,460−1.3%Reduced
Vident Advisory, LLC388,862$10.1M0.09%+6,322+1.7%Added
De Lisle Partners LLP379,818$9.90M1.18%+379,818New
Legacy Advisors, LLC9,064,278$9.06M1.07%−750,011−7.6%Reduced
Aristotle Capital Boston, LLC344,976$9.02M0.56%−13,891−3.9%Reduced
Legal & General Group Plc334,896$8.73M0.00%−33,709−9.1%Reduced
Hotchkis & Wiley Capital Management LLC333,800$8.71M0.03%+65,425+24.4%Added
Mawer Investment Management Ltd.333,790$8.71M0.06%+333,790New
Susquehanna International Group, LLP330,049$8.61M0.01%+330,049New
Ameriprise Financial Inc329,745$8.60M0.00%−8,854−2.6%Reduced
Rovida Investment Management Ltd315,000$8.21M1.03%+315,000New
Swiss National Bank313,391$8.17M0.00%+1,600+0.5%Added
Hyperion Capital Advisors LP303,576$7.92M3.81%−188,296−38.3%Reduced
Rhumbline Advisers300,293$7.83M0.01%+8,852+3.0%Added
Exchange Traded Concepts, LLC295,008$7.69M0.06%−15,513−5.0%Reduced
SEI Investments Co294,668$7.69M0.01%+77,624+35.8%Added
Grizzlyrock Capital, LLC289,113$7.54M5.97%+4,000+1.4%Added
California Public Employees Retirement System277,052$7.23M0.00%−1,592−0.6%Reduced
SG Americas Securities, LLC274,602$7.16M0.01%−70,739−20.5%Reduced
Fifth Third Bancorp273,316$7.13M0.01%+270,727+10,456.8%Added
UBS Asset Management Americas Inc247,957$6.47M0.00%−5,059−2.0%Reduced
Raymond James Financial Inc245,824$6.41M0.00%+77,779+46.3%Added
First National Bank of Omaha248,004$6.30M0.19%+70,304+39.6%Added
Soviero Asset Management, LP240,000$6.26M3.51%+62,000+34.8%Added
AWH Capital, L.P.235,250$6.14M5.57%00.0%Unchanged
Royal Bank of Canada231,742$6.04M0.00%−34,801−13.1%Reduced
First Trust Advisors LP228,083$5.95M0.00%−149,745−39.6%Reduced
Susquehanna Fundamental Investments, LLC217,780$5.68M0.21%−2,151−1.0%Reduced
Hudson Value Partners, LLC203,910$5.32M1.59%+15,917+8.5%Added
Jane Street Group, LLC191,979$5.01M0.01%+181,170+1,676.1%Added
Telos Capital Management, Inc.189,901$4.95M0.47%+2,435+1.3%Added
California State Teachers Retirement System184,555$4.81M0.01%+34,643+23.1%Added
Hel Ved Capital Management Ltd178,500$4.66M0.81%+178,500New
North Growth Management Ltd.172,000$4.47M0.69%+74,000+75.5%Added
OpenArc Corporate Advisory, LLC170,352$4.44M0.06%−29,973−15.0%Reduced
Oppenheimer & Co Inc168,872$4.40M0.05%+168,872New
New York State Teachers Retirement System165,329$4.31M0.01%−728−0.4%Reduced
Wedge Capital Management L L P164,666$4.29M0.08%+164,666New
Quantinno Capital Management LP145,574$3.80M0.01%+67,603+86.7%Added
Price T Rowe Associates Inc145,253$3.79M0.00%+15,771+12.2%Added
CenterBook Partners LP143,698$3.75M0.20%−78,525−35.3%Reduced
Prudential Financial Inc140,430$3.66M0.00%−1,992−1.4%Reduced
Vanguard Asset Management, Ltd127,793$3.33M0.00%+127,793New
Bessemer Group Inc125,952$3.28M0.01%+124,213+7,142.8%Added
Holocene Advisors, LP123,197$3.21M0.01%+43,876+55.3%Added
South Dakota Investment Council123,037$3.21M0.06%00.0%Unchanged