PCM
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Portolan Capital Management’s ACM Research ACMR Stock Holding History

Portolan Capital Management’s Portfolio ACMR Stock Details ACMR Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$22.5M Buy
177,432
+94,176
+113% +$6.66M 0.84% 39
2026
Q1 		$3.28M Sell
83,256
-202,250
-71% -$10.7M 0.17% 116
2025
Q4 		$11.3M Sell
285,506
-120,354
-30% -$4.48M 0.6% 58
2025
Q3 		$15.9M Buy
+405,860
New +$12M 0.86% 37
2024
Q4 		– Sell
-921,451
Closed -$18.7M – 132
2024
Q3 		$18.7M Buy
921,451
+65,616
+8% +$1.26M 1.36% 20
2024
Q2 		$19.7M Buy
855,835
+317,402
+59% +$8.03M 1.63% 15
2024
Q1 		$15.7M Sell
538,433
-261,071
-33% -$5.98M 1.2% 30
2023
Q4 		$15.6M Buy
+799,504
New +$14M 1.37% 18
2023
Q2 		– Sell
-561,894
Closed -$6.57M – 121
2023
Q1 		$6.57M Buy
+561,894
New +$6.5M 0.63% 56

Other funds holding ACMR

BlackRock
BlackRock New York $6.73T AUM 46.02% 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
Capital World Investors
Capital World Investors Los Angeles, California $846B AUM 46.74% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return
Invesco
Invesco Atlanta, Georgia $1.26T AUM 61.52% 1-Year Est. Return
VARA
Value Aligned Research Advisors Princeton, New Jersey $40.1B AUM 376.19% 1-Year Est. Return
WA
WFM Asia Road Town, Tortola, British Virgin Islands $663M AUM 15.46% 1-Year Est. Return
Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return

Portolan Capital Management's ACMR Position: Q2 2026 in Review

Portolan Capital Management increased its ACM Research (ACMR) stake by 113% in Q2 2026, buying an estimated $6.66M and bringing the position to 177,432 shares worth $22.5M. The position accounts for 0.84% of the portfolio, ranked #39.

Portolan Capital Management first reported a position in ACMR in Q1 2023 and has held it in 9 quarters since. 376 funds tracked by Wall St. Rank hold ACMR as of Q2 2026.

  • Portolan Capital Management held 177,432 shares of ACM Research worth $22.5M as of Q2 2026.
  • Portolan Capital Management bought 94,176 ACM Research shares in Q2 2026, an estimated $6.66M.
  • ACM Research made up 0.84% of Portolan Capital Management's portfolio in Q2 2026, its #39 holding.
  • Portolan Capital Management first reported a position in ACM Research in Q1 2023 and has held it in 9 quarters since.
  • 376 funds tracked by Wall St. Rank held ACM Research as of Q2 2026.

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