Simplex Trading
AMTM

Simplex Trading’s Amentum Holdings AMTM Stock Holding History

Simplex Trading’s Portfolio AMTM Stock Details AMTM Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$351K Buy
+17,003
New +$411K ﹤0.01% 4034
2025
Q2 		– Sell
-52,827
Closed -$1.1M – 9957
2025
Q1 		$961K Sell
52,827
-167,154
-76% -$3.4M ﹤0.01% 2741
2024
Q4 		$4.63M Buy
+219,981
New +$5.69M ﹤0.01% 1529

Other funds holding AMTM

AS
American Securities New York $3.75B AUM 23.12% 1-Year Est. Return
Invesco
Invesco Atlanta, Georgia $1.26T AUM 61.52% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
Primecap Management
Primecap Management Pasadena, California $169B AUM 114.72% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $3.38T AUM 44.17% 1-Year Est. Return
FCM
Frontier Capital Management Boston, Massachusetts $10.7B AUM 67.78% 1-Year Est. Return

Simplex Trading's AMTM Position: Q2 2026 in Review

Simplex Trading opened a new position in Amentum Holdings (AMTM) in Q2 2026: 17,003 shares worth $351K. The stake represents ﹤0.01% of the portfolio and ranks #4034 among its holdings. This is a return to the name: Simplex Trading previously reported a position in AMTM as recently as Q1 2025.

Simplex Trading first reported a position in AMTM in Q4 2024 and has held it in 3 quarters since. The position peaked at $4.63M in Q4 2024. 464 funds tracked by Wall St. Rank hold AMTM as of Q2 2026.

  • Simplex Trading held 17,003 shares of Amentum Holdings worth $351K as of Q2 2026.
  • Amentum Holdings was a new Simplex Trading position in Q2 2026.
  • Amentum Holdings made up ﹤0.01% of Simplex Trading's portfolio in Q2 2026, its #4034 holding.
  • Simplex Trading first reported a position in Amentum Holdings in Q4 2024 and has held it in 3 quarters since.
  • Simplex Trading's Amentum Holdings position peaked at $4.63M in Q4 2024.
  • 464 funds tracked by Wall St. Rank held Amentum Holdings as of Q2 2026.

Based on Simplex Trading's 13F filing for Q2 2026, filed 12 Aug 2026.