GI
AMTM

GAMCO Investors’s Amentum Holdings AMTM Stock Holding History

GAMCO Investors’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 		$2.01M Buy
97,120
+1,789
+2% +$43.3K 0.02% 499
2026
Q1 		$2.49M Buy
95,331
+3,470
+4% +$109K 0.02% 486
2025
Q4 		$2.66M Sell
91,861
-7,782
-8% -$199K 0.03% 485
2025
Q3 		$2.39M Sell
99,643
-9,027
-8% -$220K 0.02% 491
2025
Q2 		$2.57M Buy
+108,670
New +$2.27M 0.03% 486

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 $3.37T AUM 44.26% 1-Year Est. Return
FCM
Frontier Capital Management Boston, Massachusetts $10.7B AUM 67.78% 1-Year Est. Return

GAMCO Investors's AMTM Position: Q2 2026 in Review

GAMCO Investors increased its Amentum Holdings (AMTM) stake by 1.9% in Q2 2026, buying an estimated $43.3K and bringing the position to 97,120 shares worth $2.01M. The position accounts for 0.02% of the portfolio, ranked #499.

GAMCO Investors first reported a position in AMTM in Q2 2025 and has held it in 5 quarters since. The position peaked at $2.66M in Q4 2025. 460 funds tracked by Wall St. Rank hold AMTM as of Q2 2026.

  • GAMCO Investors held 97,120 shares of Amentum Holdings worth $2.01M as of Q2 2026.
  • GAMCO Investors bought 1,789 Amentum Holdings shares in Q2 2026, an estimated $43.3K.
  • Amentum Holdings made up 0.02% of GAMCO Investors's portfolio in Q2 2026, its #499 holding.
  • GAMCO Investors first reported a position in Amentum Holdings in Q2 2025 and has held it in 5 quarters since.
  • GAMCO Investors's Amentum Holdings position peaked at $2.66M in Q4 2025.
  • 460 funds tracked by Wall St. Rank held Amentum Holdings as of Q2 2026.

Based on GAMCO Investors's 13F filing for Q2 2026, filed 12 Aug 2026.