BIIB β€” BIOGEN INC

Ownership history in FOX RUN MANAGEMENT, L.L.C.  Β·  13 quarters on record

This page tracks every 13F SEC filing in which FOX RUN MANAGEMENT, L.L.C. reported a position in BIOGEN INC (BIIB). Data includes quarterly share count, position size as % of portfolio, estimated market value, and end-of-quarter stock price β€” sourced directly from SEC EDGAR 13F filings.

πŸ” Peak position
0.34% (2024 Q3)
πŸ“Š Avg. % of fund
0.22%
πŸ“… First filed
2018 Q4
πŸ“… Last filed
2025 Q3
⏱ Quarters held
13

Position Intelligence

FOX RUN MANAGEMENT, L.L.C. Γ— BIIB AI Analytics

πŸ“‰ FOX RUN MANAGEMENT, L.L.C. underperformed the S&P 500 by –59.0% annually on this BIIB position. Timing score: 42% (5/12 decisions correct). Average cost basis: $189.15. Maximum drawdown during holding period: –58.3%.

πŸ“ˆ Position Alpha vs SPY
-59.0%
annualised excess return

❌ Significantly underperformed the S&P 500 by 59.0% ann.
12 quarters analyzed

⏱️ Timing Score
42%

⚠️ Poor timing β€” buys often preceded drops, trims preceded rallies.
5 of 12 add/trim decisions correct

πŸ’° Entry Quality
$189.15
-25.9% vs current ($140.08)

Best entry: $125.59 (2025 Q2)  Β·  Worst: $300.92 (2018 Q4)

πŸ›‘οΈ Drawdown Resilience
–58.3%
max drawdown while held

πŸ’ͺ Held through 1 major drawdown (>20%). Strong conviction under pressure.

πŸ’ͺ Fund Conviction
69%
buy-side decisions

9 adds Β· 4 trims. Bought during 7 of 8 down-price quarters. πŸ“ˆ More buys than sells across the holding period.

πŸ“‘ Position Trajectory
β†’ Stable
last 4–5 quarters trend

βš–οΈ Portfolio weight has remained relatively stable β€” conviction maintained.
Currently 0.15% of portfolio

⚠ Based on quarterly 13F SEC filings and end-of-quarter closing prices. Timing score = accuracy of add/trim decisions vs next-quarter price direction. Alpha = mean quarterly excess return Γ— 4 (annualised). Not investment advice.

% of Fund (quarterly)    BIIB price (monthly, adj. close)
πŸ“‹ Quarterly Holdings History 10 quarters  β–Ύ
Quarter Action Shares Change Chg % % of Fund Mkt Value Price (EOQ)
2025 Q3 REDUCED 6,969 -5,922 -45.9% 0.15% $976K $140.08
2025 Q2 ADDED 12,891 +3,777 +41.4% 0.27% $1.6M $125.59
2025 Q1 ADDED 9,114 +1,192 +15.0% 0.19% $1.2M $136.84
2024 Q3 ADDED 7,922 +5,948 +301.3% 0.34% $1.5M $193.84
2024 Q1 REDUCED 1,974 -406 -17.1% 0.09% $426K $215.63
2023 Q2 ADDED 2,380 +526 +28.4% 0.19% $678K $284.85
2022 Q4 REDUCED 1,854 -1,008 -35.2% 0.21% $513K $276.92
2022 Q2 ADDED 2,862 +1,255 +78.1% 0.29% $584K $203.94
2022 Q1 ADDED 1,607 +900 +127.3% 0.19% $338K $210.60
2021 Q3 REDUCED 707 -1,563 -68.9% 0.13% $200K $282.99
3 older quarters hidden  β€”  Sign in free or upgrade to Premium to see full history

🏒 Other funds also holding BIIB

As of 2025 Q4 β€” sorted by position size

Palo Alto Investors LP 3Y 7Y 4.5% BRIDGER MANAGEMENT, LLC 3Y 7Y 4.08% Patient Capital Management, LLC 3Y 3.92% SECTOR GAMMA AS 3Y 7Y 3.43% Hillman Capital Management, Inc. 3Y 7Y 3.38% SPHERA FUNDS MANAGEMENT LTD. 3Y 7Y 3.22% Privium Fund Management B.V. 3Y 2.38% Logos Global Management LP 3Y 2.13% Orion Investment Co 2.11% PRIMECAP MANAGEMENT CO/CA/ 3Y 7Y 1.97%
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