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ADAR1 Capital Management’s Biogen BIIB Stock Holding History

ADAR1 Capital Management’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
Q2 		$3.87M Buy
17,900
+6,900
+63% +$1.32M 0.18% 113
2026
Q1 		$2.02M Sell
11,000
-13,300
-55% -$2.45M 0.12% 121
2025
Q4 		$4.28M Buy
24,300
+6,300
+35% +$1.03M 0.31% 65
2025
Q3 		$2.52M Buy
18,000
+12,900
+253% +$1.74M 0.24% 70
2025
Q2 		$641K Buy
5,100
+600
+13% +$74.8K 0.1% 105
2025
Q1 		$616K Buy
4,500
+1,455
+48% +$208K 0.11% 93
2024
Q4 		$466K Sell
3,045
-26,580
-90% -$4.48M 0.09% 114
2024
Q3 		$5.74M Buy
+29,625
New +$6.2M 0.93% 25

Other funds holding BIIB

Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 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

ADAR1 Capital Management's BIIB Position: Q2 2026 in Review

ADAR1 Capital Management increased its Biogen (BIIB) stake by 63% in Q2 2026, buying an estimated $1.32M and bringing the position to 17,900 shares worth $3.87M. The position accounts for 0.18% of the portfolio, ranked #113.

ADAR1 Capital Management first reported a position in BIIB in Q3 2024 and has held it in 8 quarters since. The position peaked at $5.74M in Q3 2024. 1,045 funds tracked by Wall St. Rank hold BIIB as of Q2 2026.

  • ADAR1 Capital Management held 17,900 shares of Biogen worth $3.87M as of Q2 2026.
  • ADAR1 Capital Management bought 6,900 Biogen shares in Q2 2026, an estimated $1.32M.
  • Biogen made up 0.18% of ADAR1 Capital Management's portfolio in Q2 2026, its #113 holding.
  • ADAR1 Capital Management first reported a position in Biogen in Q3 2024 and has held it in 8 quarters since.
  • ADAR1 Capital Management's Biogen position peaked at $5.74M in Q3 2024.
  • 1,045 funds tracked by Wall St. Rank held Biogen as of Q2 2026.

Based on ADAR1 Capital Management's 13F filing for Q2 2026, filed 14 Aug 2026.