Frontier Capital Management’s Amentum Holdings AMTM Stock Holding History

Frontier Capital Management’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	$85.7M	Sell	4,143,971 -786,239	-16%	-$19M	0.8%	26
2026 Q1	$129M	Sell	4,930,210 -842,766	-15%	-$26.4M	1.32%	7
2025 Q4	$167M	Buy	5,772,976 +570,296	+11%	+$14.6M	1.78%	2
2025 Q3	$125M	Sell	5,202,680 -258,063	-5%	-$6.28M	1.12%	14
2025 Q2	$129M	Buy	5,460,743 +1,882,011	+53%	+$39.3M	1.19%	6
2025 Q1	$65.1M	Buy	+3,578,732	New	+$72.9M	0.71%	35

Other funds holding AMTM

American Securities New York $3.75B AUM 23.12% 1-Year Est. Return

Invesco Atlanta, Georgia $1.26T AUM 61.52% 1-Year Est. Return

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Primecap Management Pasadena, California $169B AUM 114.72% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

TCA

Troluce Capital Advisors Dorado, Puerto Rico $971M AUM 2.27% 1-Year Est. Return

Frontier Capital Management's AMTM Position: Q2 2026 in Review

Frontier Capital Management reduced its Amentum Holdings (AMTM) stake by 16% in Q2 2026, selling an estimated $19M and leaving 4,143,971 shares worth $85.7M. The position accounts for 0.8% of the portfolio, ranked #26.

Frontier Capital Management first reported a position in AMTM in Q1 2025 and has held it in 6 quarters since. The position peaked at $167M in Q4 2025. 461 funds tracked by Wall St. Rank hold AMTM as of Q2 2026.

Frontier Capital Management held 4,143,971 shares of Amentum Holdings worth $85.7M as of Q2 2026.
Frontier Capital Management sold 786,239 Amentum Holdings shares in Q2 2026, an estimated $19M.
Amentum Holdings made up 0.8% of Frontier Capital Management's portfolio in Q2 2026, its #26 holding.
Frontier Capital Management first reported a position in Amentum Holdings in Q1 2025 and has held it in 6 quarters since.
Frontier Capital Management's Amentum Holdings position peaked at $167M in Q4 2025.
461 funds tracked by Wall St. Rank held Amentum Holdings as of Q2 2026.

Based on Frontier Capital Management's 13F filing for Q2 2026, filed 14 Aug 2026.