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Cubist Systematic Strategies’s iRhythm Holdings IRTC Stock Holding History

Cubist Systematic Strategies’s Portfolio IRTC Stock Details IRTC Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2025
Q1 		– Sell
-7,700
Closed -$694K – 3167
2024
Q4 		$694K Sell
7,700
-6,300
-45% -$495K ﹤0.01% 2020
2024
Q3 		$1.04M Buy
+14,000
New +$1.12M 0.01% 1812

Other funds holding IRTC

Vanguard Group
Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return
BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
Artisan Partners
Artisan Partners Milwaukee, Wisconsin $62.3B AUM 26.25% 1-Year Est. Return
Sands Capital Management
Sands Capital Management Arlington, Virginia $25.5B AUM 26.46% 1-Year Est. Return
Capital Research Global Investors
Capital Research Global Investors Los Angeles, California $645B AUM 30.41% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
William Blair & Company
William Blair & Company Chicago, Illinois $34.9B AUM 18.88% 1-Year Est. Return
EAM
Eventide Asset Management Boston, Massachusetts $6.05B AUM 76.64% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

Cubist Systematic Strategies's IRTC Position: Q3 2025 in Review

Cubist Systematic Strategies reduced its iRhythm Holdings (IRTC) stake by 19% in Q3 2025, selling an estimated $3.42M and leaving 89,220 shares worth $15.3M. The position accounts for 0.07% of the portfolio, ranked #372.

Cubist Systematic Strategies first reported a position in IRTC in Q3 2017 and has held it in 26 quarters since. The position peaked at $17M in Q2 2025. 337 funds tracked by Wall St. Rank hold IRTC as of Q3 2025.

  • Cubist Systematic Strategies held 89,220 shares of iRhythm Holdings worth $15.3M as of Q3 2025.
  • Cubist Systematic Strategies sold 21,507 iRhythm Holdings shares in Q3 2025, an estimated $3.42M.
  • iRhythm Holdings made up 0.07% of Cubist Systematic Strategies's portfolio in Q3 2025, its #372 holding.
  • Cubist Systematic Strategies first reported a position in iRhythm Holdings in Q3 2017 and has held it in 26 quarters since.
  • Cubist Systematic Strategies's iRhythm Holdings position peaked at $17M in Q2 2025.
  • 337 funds tracked by Wall St. Rank held iRhythm Holdings as of Q3 2025.

Based on Cubist Systematic Strategies's 13F filing for Q3 2025, filed 14 Nov 2025.