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Rock Springs Capital Management’s Alnylam Pharmaceuticals ALNY Stock Holding History

Rock Springs Capital Management’s Portfolio ALNY Stock Details ALNY Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2024
Q2 		– Sell
-32,500
Closed -$4.86M – 113
2024
Q1 		$4.86M Buy
+32,500
New +$5.42M 0.12% 93

Other funds holding ALNY

Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return
Capital World Investors
Capital World Investors Los Angeles, California $733B AUM 35.63% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
Capital Research Global Investors
Capital Research Global Investors Los Angeles, California $645B AUM 30.41% 1-Year Est. Return
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
JP Morgan Chase
JP Morgan Chase New York $1.56T AUM 27.86% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
T. Rowe Price Investment Management
T. Rowe Price Investment Management Baltimore, Maryland $145B AUM 22.78% 1-Year Est. Return
Invesco
Invesco Atlanta, Georgia $1.02T AUM 30.18% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Rock Springs Capital Management's ALNY Position: Q1 2026 in Review

Rock Springs Capital Management increased its Alnylam Pharmaceuticals (ALNY) stake by 3.9% in Q1 2026, buying an estimated $936K and bringing the position to 74,000 shares worth $24.5M. The position accounts for 1.44% of the portfolio, ranked #21.

Rock Springs Capital Management first reported a position in ALNY in Q2 2017 and has held it in 36 quarters since. The position peaked at $79M in Q4 2022. 789 funds tracked by Wall St. Rank hold ALNY as of Q1 2026.

  • Rock Springs Capital Management held 74,000 shares of Alnylam Pharmaceuticals worth $24.5M as of Q1 2026.
  • Rock Springs Capital Management bought 2,750 Alnylam Pharmaceuticals shares in Q1 2026, an estimated $936K.
  • Alnylam Pharmaceuticals made up 1.44% of Rock Springs Capital Management's portfolio in Q1 2026, its #21 holding.
  • Rock Springs Capital Management first reported a position in Alnylam Pharmaceuticals in Q2 2017 and has held it in 36 quarters since.
  • Rock Springs Capital Management's Alnylam Pharmaceuticals position peaked at $79M in Q4 2022.
  • 789 funds tracked by Wall St. Rank held Alnylam Pharmaceuticals as of Q1 2026.

Based on Rock Springs Capital Management's 13F filing for Q1 2026, filed 15 May 2026.