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SIH Partners’s Biogen BIIB Stock Holding History

SIH Partners’s Portfolio BIIB Stock Details BIIB Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		$268K Buy
+1,463
New +$270K ﹤0.01% 255
2025
Q2 		– Sell
-10,414
Closed -$1.43M – 186
2025
Q1 		$1.43M Buy
+10,414
New +$1.49M 0.05% 103

Other funds holding BIIB

BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
Primecap Management
Primecap Management Pasadena, California $127B AUM 44.11% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
Wellington Management Group
Wellington Management Group Boston, Massachusetts $535B AUM 26.23% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.66T AUM 25.57% 1-Year Est. Return
JP Morgan Chase
JP Morgan Chase New York $1.56T AUM 27.86% 1-Year Est. Return

SIH Partners's BIIB Position: Q1 2026 in Review

SIH Partners opened a new position in Biogen (BIIB) in Q1 2026: 1,463 shares worth $268K. The stake represents ﹤0.01% of the portfolio and ranks #255 among its holdings. This is a return to the name: SIH Partners previously reported a position in BIIB as recently as Q1 2025.

SIH Partners first reported a position in BIIB in Q1 2025 and has held it in 2 quarters since. The position peaked at $1.43M in Q1 2025. 1,002 funds tracked by Wall St. Rank hold BIIB as of Q1 2026.

  • SIH Partners held 1,463 shares of Biogen worth $268K as of Q1 2026.
  • Biogen was a new SIH Partners position in Q1 2026.
  • Biogen made up ﹤0.01% of SIH Partners's portfolio in Q1 2026, its #255 holding.
  • SIH Partners first reported a position in Biogen in Q1 2025 and has held it in 2 quarters since.
  • SIH Partners's Biogen position peaked at $1.43M in Q1 2025.
  • 1,002 funds tracked by Wall St. Rank held Biogen as of Q1 2026.

Based on SIH Partners's 13F filing for Q1 2026, filed 15 May 2026.