Group One Trading’s Amentum Holdings AMTM Stock Holding History

Group One 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	$660K	Sell	36,400 -88,700	-71%	-$1.86M	﹤0.01%	3156
2026 Q2	$2.59M	Sell	125,100 -41,900	-25%	-$1.01M	﹤0.01%	1991
2026 Q1	$4.36M	Buy	167,000 +20,700	+14%	+$650K	0.01%	1408
2025 Q4	$4.24M	Buy	146,300 +64,800	+80%	+$1.66M	0.01%	1652
2025 Q3	$1.95M	Sell	81,500 -128,500	-61%	-$3.13M	﹤0.01%	2341
2025 Q2	$4.96M	Sell	210,000 -344,200	-62%	-$7.19M	0.01%	1333
2025 Q1	$10.1M	Buy	554,200 +503,600	+995%	+$10.3M	0.03%	621
2024 Q4	$1.06M	Buy	+50,600	New	+$1.31M	﹤0.01%	2521

Other funds holding AMTM

American Securities New York $2.69B AUM 8.08% 1-Year Est. Return

Invesco Atlanta, Georgia $1.27T AUM 50.62% 1-Year Est. Return

BlackRock New York $6.79T AUM 37.06% 1-Year Est. Return

Primecap Management Pasadena, California $161B AUM 86.05% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.21T AUM

Dimensional Fund Advisors Austin, Texas $551B AUM 33.95% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.76T AUM

Fidelity Investments Boston, Massachusetts $2.32T AUM 44.66% 1-Year Est. Return

State Street Boston, Massachusetts $3.44T AUM 36.12% 1-Year Est. Return

Thompson Siegel & Walmsley Richmond, Virginia $5.37B AUM 3.99% 1-Year Est. Return

Group One Trading's AMTM Position: Q3 2026 in Review

Group One Trading reduced its Amentum Holdings (AMTM) stake by 68% in Q3 2026, selling an estimated $394K and leaving 8,882 shares worth $161K. The position accounts for ﹤0.01% of the portfolio, ranked #4352.

Group One Trading first reported a position in AMTM in Q3 2024 and has held it in 8 quarters since. The position peaked at $1.91M in Q1 2025. 360 funds tracked by Wall St. Rank hold AMTM as of Q3 2026.

Group One Trading held 8,882 shares of Amentum Holdings worth $161K as of Q3 2026.
Group One Trading sold 18,828 Amentum Holdings shares in Q3 2026, an estimated $394K.
Amentum Holdings made up ﹤0.01% of Group One Trading's portfolio in Q3 2026, its #4352 holding.
Group One Trading first reported a position in Amentum Holdings in Q3 2024 and has held it in 8 quarters since.
Group One Trading's Amentum Holdings position peaked at $1.91M in Q1 2025.
360 funds tracked by Wall St. Rank held Amentum Holdings as of Q3 2026.

Based on Group One Trading's 13F filing for Q3 2026, filed 10 Nov 2026.