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© 2026 DataHeimdall. All rights reserved.Data sourced from SEC EDGAR public filings.
Insider Trades

BIIB

BIOGEN INC.

Superinvestors

Institutional investors holding BIIB

Consensus →
InvestorFundWeightSharesValueQuarter
Carl IcahnIcahn Capital Management16.64%8,825,816$585.4M2007Q3
Hillman Capital ManagementHillman Value Fund3.76%29,540$5.4M2026Q1
Mason HawkinsLongleaf Partners – Southeastern Asset Management3.14%842,962$177.5M2022Q1
Michael BurryScion Asset Management2.91%10,000$3.0M2018Q4
Samantha McLemorePatient Capital Management2.55%379,741$69.6M2026Q1
Viking Global InvestorsViking Global Investors0.83%688,765$188.3M2017Q1
Bill MillerMiller Value Partners0.66%79,493$27.5M2021Q2
Sarah KettererCauseway Capital Management0.63%280,783$51.5M2026Q1
William Von MuefflingCantillon Capital Management0.18%74,796$5.0M2004Q4
Duan YongpingH&H International Investment0.11%10,000$3.2M2020Q1
Warren BuffettBerkshire Hathaway0.07%643,022$179.9M2021Q1
First Eagle Investment ManagementFirst Eagle Investment Management0.05%57,300$15.3M2020Q2
Kenneth FisherFisher Asset Management0.02%312,618$57.3M2026Q1
Meridian / ArrowMarkMeridian Contrarian Fund0.01%1,475$596K2015Q2
Christopher DavisDavis Selected Advisers0.00%0$1.8M2008Q2
Richard PzenaPzena Investment Management0.00%1,618$461K2023Q2
Mairs & PowerMairs & Power Growth Fund0.00%950$246K2023Q4
Dodge & CoxDodge & Cox0.00%6,000$302K2008Q3

Congressional Activity

Congressional data coming soon

Insider Activity

4

Total trades

$95K

Volume

0

Buys

2

Sells

Last trade: May 1, 2026

Insider Tradeslast 90 days

DateInsiderTypeValue
May 1, 2026Adam KeeneyOption–
May 1, 2026Adam KeeneySell$85K

Congressional Tradeslast 90 days

Congressional trade data is being sourced and will appear here shortly.

Apr 1, 2026
Adam Keeney
Option
–
Apr 1, 2026Adam KeeneySell$10K