BlackRock
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BlackRock’s Biogen BIIB Stock Holding History

BlackRock’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
2022
Q1 		– Sell
-15,000
Closed -$3.6M – 5815
2021
Q4 		$3.6M Buy
+15,000
New +$3.86M ﹤0.01% 4139
2016
Q4 		– Sell
-200
Closed -$63K – 3733
2016
Q3 		$63K Buy
+200
New +$59.2K ﹤0.01% 2853

Other funds holding BIIB

Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
Primecap Management
Primecap Management Pasadena, California $169B AUM 114.72% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return
Wellington Management Group
Wellington Management Group Boston, Massachusetts $580B AUM 38.23% 1-Year Est. Return
Norges Bank
Norges Bank Oslo, Norway $1T AUM
Morgan Stanley
Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return
AQR Capital Management
AQR Capital Management Greenwich, Connecticut $287B AUM 42.33% 1-Year Est. Return

BlackRock's BIIB Position: Q2 2026 in Review

BlackRock increased its Biogen (BIIB) stake by 0.07% in Q2 2026, buying an estimated $2.13M and bringing the position to 15,985,736 shares worth $3.45B. The position accounts for 0.05% of the portfolio, ranked #290.

BlackRock first reported a position in BIIB in Q2 2013 and has held it in 53 quarters since. The position peaked at $5.83B in Q3 2018. 1,042 funds tracked by Wall St. Rank hold BIIB as of Q2 2026.

  • BlackRock held 15,985,736 shares of Biogen worth $3.45B as of Q2 2026.
  • BlackRock bought 11,135 Biogen shares in Q2 2026, an estimated $2.13M.
  • Biogen made up 0.05% of BlackRock's portfolio in Q2 2026, its #290 holding.
  • BlackRock first reported a position in Biogen in Q2 2013 and has held it in 53 quarters since.
  • BlackRock's Biogen position peaked at $5.83B in Q3 2018.
  • 1,042 funds tracked by Wall St. Rank held Biogen as of Q2 2026.

Based on BlackRock's 13F filing for Q2 2026, filed 7 Aug 2026.