Mariner
AMTM

Mariner’s Amentum Holdings AMTM Stock Holding History

Mariner’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
Q1 		– Sell
-48,837
Closed -$1.42M – 3883
2025
Q4 		$1.42M Buy
48,837
+8,195
+20% +$209K ﹤0.01% 1703
2025
Q3 		$973K Sell
40,642
-2,347
-5% -$57.1K ﹤0.01% 1927
2025
Q2 		$1.01M Buy
42,989
+11,260
+35% +$235K ﹤0.01% 1773
2025
Q1 		$577K Sell
31,729
-7,155
-18% -$146K ﹤0.01% 2092
2024
Q4 		$818K Sell
38,884
-26,019
-40% -$673K ﹤0.01% 1795
2024
Q3 		$2.09M Buy
+64,903
New +$1.85M ﹤0.01% 1162

Other funds holding AMTM

AS
American Securities New York $3.93B AUM 52.22% 1-Year Est. Return
Invesco
Invesco Atlanta, Georgia $1.02T AUM 30.18% 1-Year Est. Return
BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
Primecap Management
Primecap Management Pasadena, California $127B AUM 44.11% 1-Year Est. Return
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
FCM
Frontier Capital Management Boston, Massachusetts $9.73B AUM 55.65% 1-Year Est. Return
Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $481B AUM 30.42% 1-Year Est. Return

Mariner's AMTM Position: Q1 2026 in Review

Mariner sold out of Amentum Holdings (AMTM) in Q1 2026, closing a stake of 48,837 shares — an estimated $1.42M sold.

Mariner first reported a position in AMTM in Q3 2024 and held it in 6 quarters. The position peaked at $2.09M in Q3 2024. 486 funds tracked by Wall St. Rank hold AMTM as of Q1 2026.

  • Mariner reported no remaining Amentum Holdings position as of Q1 2026 after selling out during the quarter.
  • Mariner sold 48,837 Amentum Holdings shares in Q1 2026, an estimated $1.42M.
  • Mariner first reported a position in Amentum Holdings in Q3 2024 and held it in 6 quarters.
  • Mariner's Amentum Holdings position peaked at $2.09M in Q3 2024.
  • 486 funds tracked by Wall St. Rank held Amentum Holdings as of Q1 2026.

Based on Mariner's 13F filing for Q1 2026, filed 13 May 2026.