Simplex Trading
AMTM icon

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
Q3 		$261K Sell
14,400
-21,900
-60% -$459K ﹤0.01% 4320
2026
Q2 		$750K Buy
36,300
+26,300
+263% +$636K ﹤0.01% 3109
2026
Q1 		$261K Sell
10,000
-10,800
-52% -$339K ﹤0.01% 3980
2025
Q4 		$603K Sell
20,800
-2,500
-11% -$63.9K ﹤0.01% 3117
2025
Q3 		$558K Sell
23,300
-31,600
-58% -$769K ﹤0.01% 3693
2025
Q2 		$1.3M Sell
54,900
-93,100
-63% -$1.95M ﹤0.01% 2510
2025
Q1 		$2.69M Sell
148,000
-220,700
-60% -$4.5M ﹤0.01% 1764
2024
Q4 		$7.75M Buy
+368,700
New +$9.5M ﹤0.01% 1186

Other funds holding AMTM

Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $551B AUM 33.95% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.32T AUM 44.66% 1-Year Est. Return
Thompson Siegel & Walmsley
Thompson Siegel & Walmsley Richmond, Virginia $5.37B AUM 3.99% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.92T AUM 36.1% 1-Year Est. Return
UBS Group
UBS Group Zurich, Switzerland $765B AUM 28.39% 1-Year Est. Return
Cacti Asset Management
Cacti Asset Management Atlanta, Georgia $1.89B AUM 58.55% 1-Year Est. Return
Bank of New York Mellon
Bank of New York Mellon New York $608B AUM 32.77% 1-Year Est. Return
River Road Asset Management
River Road Asset Management Louisville, Kentucky $8.42B AUM 5.65% 1-Year Est. Return
Segra Capital Management
Segra Capital Management Palm Beach, Florida $822M AUM 57.18% 1-Year Est. Return
Principal Financial Group
Principal Financial Group Des Moines, Iowa $195B AUM 21.17% 1-Year Est. Return

Simplex Trading's AMTM Position: Q3 2026 in Review

Simplex Trading sold out of Amentum Holdings (AMTM) in Q3 2026, closing a stake of 17,003 shares — an estimated $356K sold.

Simplex Trading first reported a position in AMTM in Q4 2024 and held it in 3 quarters. The position peaked at $4.63M in Q4 2024. 252 funds tracked by Wall St. Rank hold AMTM as of Q3 2026.

  • Simplex Trading reported no remaining Amentum Holdings position as of Q3 2026 after selling out during the quarter.
  • Simplex Trading sold 17,003 Amentum Holdings shares in Q3 2026, an estimated $356K.
  • Simplex Trading first reported a position in Amentum Holdings in Q4 2024 and held it in 3 quarters.
  • Simplex Trading's Amentum Holdings position peaked at $4.63M in Q4 2024.
  • 252 funds tracked by Wall St. Rank held Amentum Holdings as of Q3 2026.

Based on Simplex Trading's 13F filing for Q3 2026, filed 4 Nov 2026.