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
2014 Q2	–	Sell	-2,900	Closed	-$887K	–	3159
2014 Q1	$887K	Buy	+2,900	New	+$921K	﹤0.01%	1229

Other funds holding BIIB

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

Primecap Management Pasadena, California $169B AUM 114.72% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

Wellington Management Group Boston, Massachusetts $580B AUM 38.23% 1-Year Est. Return

Norges Bank Oslo, Norway $1T AUM

Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return

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.