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Atom Investors’s Biogen BIIB Stock Holding History

Atom Investors’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 		– Sell
-24,749
Closed -$4.54M – 843
2026
Q1 		$4.54M Buy
24,749
+3,029
+14% +$558K 0.32% 92
2025
Q4 		$3.82M Buy
21,720
+19,498
+877% +$3.19M 0.3% 113
2025
Q3 		$311K Buy
+2,222
New +$300K 0.02% 441
2025
Q1 		– Sell
-2,745
Closed -$420K – 512
2024
Q4 		$420K Buy
+2,745
New +$463K 0.05% 334
2022
Q1 		– Sell
-2,686
Closed -$644K – 212
2021
Q4 		$644K Buy
+2,686
New +$691K 0.11% 141
2021
Q1 		– Sell
-42,471
Closed -$10.4M – 257
2020
Q4 		$10.4M Buy
42,471
+23,437
+123% +$6.05M 1.05% 23
2020
Q3 		$5.4M Buy
19,034
+7,158
+60% +$2M 0.51% 41
2020
Q2 		$3.18M Sell
11,876
-20,871
-64% -$6.27M 0.21% 93
2020
Q1 		$10.4M Buy
32,747
+3,360
+11% +$1.02M 0.91% 29
2019
Q4 		$8.72M Sell
29,387
-18,176
-38% -$5.04M 0.71% 45
2019
Q3 		$11.1M Buy
47,563
+24,444
+106% +$5.69M 0.76% 35
2019
Q2 		$5.41M Buy
23,119
+20,162
+682% +$4.66M 0.35% 88
2019
Q1 		$699K Buy
+2,957
New +$931K 0.06% 220

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

Atom Investors's BIIB Position: Q2 2026 in Review

Atom Investors sold out of Biogen (BIIB) in Q2 2026, closing a stake of 24,749 shares — an estimated $4.54M sold.

Atom Investors first reported a position in BIIB in Q1 2019 and held it in 13 quarters. The position peaked at $11.1M in Q3 2019. 1,045 funds tracked by Wall St. Rank hold BIIB as of Q2 2026.

  • Atom Investors reported no remaining Biogen position as of Q2 2026 after selling out during the quarter.
  • Atom Investors sold 24,749 Biogen shares in Q2 2026, an estimated $4.54M.
  • Atom Investors first reported a position in Biogen in Q1 2019 and held it in 13 quarters.
  • Atom Investors's Biogen position peaked at $11.1M in Q3 2019.
  • 1,045 funds tracked by Wall St. Rank held Biogen as of Q2 2026.

Based on Atom Investors's 13F filing for Q2 2026, filed 14 Aug 2026.