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XTX Topco’s Biogen BIIB Stock Holding History

XTX Topco’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 		$700K Buy
+3,239
New +$620K 0.01% 2116
2026
Q1 		– Sell
-2,459
Closed -$433K – 3852
2025
Q4 		$433K Buy
+2,459
New +$402K 0.01% 1735
2025
Q2 		– Sell
-16,743
Closed -$2.29M – 2382
2025
Q1 		$2.29M Buy
16,743
+14,459
+633% +$2.07M 0.12% 209
2024
Q4 		$349K Sell
2,284
-4,671
-67% -$788K 0.03% 1088
2024
Q3 		$1.35M Buy
+6,955
New +$1.46M 0.1% 296
2024
Q2 		– Sell
-7,176
Closed -$1.55M – 1879
2024
Q1 		$1.55M Buy
7,176
+4,036
+129% +$945K 0.21% 61
2023
Q4 		$813K Buy
3,140
+1,021
+48% +$251K 0.18% 63
2023
Q3 		$545K Sell
2,119
-265
-11% -$70.9K 0.09% 347
2023
Q2 		$679K Buy
+2,384
New +$710K 0.12% 222
2023
Q1 		– Sell
-830
Closed -$230K – 1276
2022
Q4 		$230K Sell
830
-543
-40% -$153K 0.05% 758
2022
Q3 		$367K Sell
1,373
-1,144
-45% -$243K 0.09% 382
2022
Q2 		$513K Buy
2,517
+512
+26% +$105K 0.21% 108
2022
Q1 		$422K Buy
2,005
+1,148
+134% +$250K 0.19% 182
2021
Q4 		$206K Sell
857
-1,643
-66% -$422K 0.12% 360
2021
Q3 		$707K Buy
+2,500
New +$819K 0.24% 99

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

XTX Topco's BIIB Position: Q2 2026 in Review

XTX Topco opened a new position in Biogen (BIIB) in Q2 2026: 3,239 shares worth $700K. The stake represents 0.01% of the portfolio and ranks #2116 among its holdings. This is a return to the name: XTX Topco previously reported a position in BIIB as recently as Q4 2025.

XTX Topco first reported a position in BIIB in Q3 2021 and has held it in 15 quarters since. The position peaked at $2.29M in Q1 2025. 1,041 funds tracked by Wall St. Rank hold BIIB as of Q2 2026.

  • XTX Topco held 3,239 shares of Biogen worth $700K as of Q2 2026.
  • Biogen was a new XTX Topco position in Q2 2026.
  • Biogen made up 0.01% of XTX Topco's portfolio in Q2 2026, its #2116 holding.
  • XTX Topco first reported a position in Biogen in Q3 2021 and has held it in 15 quarters since.
  • XTX Topco's Biogen position peaked at $2.29M in Q1 2025.
  • 1,041 funds tracked by Wall St. Rank held Biogen as of Q2 2026.

Based on XTX Topco's 13F filing for Q2 2026, filed 14 Aug 2026.