PEAK6
BIIB icon

PEAK6’s Biogen BIIB Stock Holding History

PEAK6’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 		$3.19M Sell
14,752
-13,414
-48% -$2.57M 0.01% 1062
2026
Q1 		$5.16M Buy
+28,166
New +$5.19M 0.01% 885
2025
Q3 		– Sell
-17,286
Closed -$2.34M – 2941
2025
Q2 		$2.17M Sell
17,286
-13,336
-44% -$1.66M ﹤0.01% 1383
2025
Q1 		$4.19M Buy
30,622
+21,871
+250% +$3.13M 0.01% 1029
2024
Q4 		$1.34M Buy
+8,751
New +$1.48M ﹤0.01% 1649

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

PEAK6's BIIB Position: Q2 2026 in Review

PEAK6 reduced its Biogen (BIIB) stake by 48% in Q2 2026, selling an estimated $2.57M and leaving 14,752 shares worth $3.19M. The position accounts for 0.01% of the portfolio, ranked #1062.

PEAK6 first reported a position in BIIB in Q4 2024 and has held it in 5 quarters since. The position peaked at $5.16M in Q1 2026. 1,043 funds tracked by Wall St. Rank hold BIIB as of Q2 2026.

  • PEAK6 held 14,752 shares of Biogen worth $3.19M as of Q2 2026.
  • PEAK6 sold 13,414 Biogen shares in Q2 2026, an estimated $2.57M.
  • Biogen made up 0.01% of PEAK6's portfolio in Q2 2026, its #1062 holding.
  • PEAK6 first reported a position in Biogen in Q4 2024 and has held it in 5 quarters since.
  • PEAK6's Biogen position peaked at $5.16M in Q1 2026.
  • 1,043 funds tracked by Wall St. Rank held Biogen as of Q2 2026.

Based on PEAK6's 13F filing for Q2 2026, filed 13 Aug 2026.