Stock Ownership/BIIB

BIOGEN INC (BIIB): Ownership & Insider Activity

Hedge funds and institutional managers reporting a position in BIIB · Health Care. Based on the most recent 13F filing from each holder, sourced from SEC EDGAR.

Reported Holders
32
13F filers
Aggregate Value
$4.4B
Across holders
Last Price
$218.12
2026-08-24
Sector
Health Care
GICS
Quarterly fund activity16 increased14 reduced5 exited
Full exits: GLENVIEW CAPITAL MANAGEMENT LLC, Alphadyne Asset Management LP, MILLENNIUM MANAGEMENT LLC, Schonfeld Strategic Advisors LLC, Qube Research & Technologies Ltd
Institutional Holders of BIIB
↗
32 holders
Manager⇅Type⇅Shares⇅Market Value▼% of Total⇅% of Portfolio⇅Action⇅QoQ Change⇅Quarter⇅
PRIMECAP MANAGEMENT CO/CA/
CIK 0000763212
Institutional Manager15.15M$3.3B74.6%1.9%Added+$85.8MQ2 2026
AQR CAPITAL MANAGEMENT LLC
CIK 0001167557
Hedge Fund1.94M$416.9M9.5%0.1%Added+$416.9MQ2 2026
FRED ALGER MANAGEMENT, LLC
CIK 0000003520
Hedge Fund788K$170.3M3.9%0.6%Added+$11.9MQ2 2026
CITADEL ADVISORS LLC
CIK 0001423053
Hedge Fund418K$90.4M2.1%0.0%Added+$70.4MQ2 2026
Fisher Asset Management, LLC
CIK 0000850529
Institutional Manager338K$73.0M1.7%0.0%Added+$5.5MQ2 2026
Gotham Asset Management, LLC
CIK 0001510387
Hedge Fund280K$60.5M1.4%0.1%Reduced$-4.0MQ2 2026
BALYASNY ASSET MANAGEMENT LLC
CIK 0001218710
Hedge Fund265K$57.3M1.3%0.1%Reduced$-83.2MQ2 2026
Man Group plc
CIK 0001637460
Hedge Fund196K$42.4M1.0%0.1%Reduced+$36.0MQ2 2026
JUPITER ASSET MANAGEMENT LTD
CIK 0001215838
Hedge Fund160K$34.6M0.8%0.2%Added+$31.5MQ2 2026
ADAGE CAPITAL PARTNERS GP, L.L.C.
CIK 0001165408
Hedge Fund130K$28.0M0.6%0.0%Reduced$-44.0MQ2 2026
PRIMECAP MANAGEMENT CO/CA/Added
Institutional Manager
$3.3B· 74.6% of total· 1.9% port· 15.15M sh· +$85.8M QoQ· Q2 2026
AQR CAPITAL MANAGEMENT LLCAdded
Hedge Fund
$416.9M· 9.5% of total· 0.1% port· 1.94M sh· +$416.9M QoQ· Q2 2026
FRED ALGER MANAGEMENT, LLCAdded
Hedge Fund
$170.3M· 3.9% of total· 0.6% port· 788K sh· +$11.9M QoQ· Q2 2026
CITADEL ADVISORS LLCAdded
Hedge Fund
$90.4M· 2.1% of total· 0.0% port· 418K sh· +$70.4M QoQ· Q2 2026
Fisher Asset Management, LLCAdded
Institutional Manager
$73.0M· 1.7% of total· 0.0% port· 338K sh· +$5.5M QoQ· Q2 2026
Gotham Asset Management, LLCReduced
Hedge Fund
$60.5M· 1.4% of total· 0.1% port· 280K sh· $-4.0M QoQ· Q2 2026
BALYASNY ASSET MANAGEMENT LLCReduced
Hedge Fund
$57.3M· 1.3% of total· 0.1% port· 265K sh· $-83.2M QoQ· Q2 2026
Man Group plcReduced
Hedge Fund
$42.4M· 1.0% of total· 0.1% port· 196K sh· +$36.0M QoQ· Q2 2026
JUPITER ASSET MANAGEMENT LTDAdded
Hedge Fund
$34.6M· 0.8% of total· 0.2% port· 160K sh· +$31.5M QoQ· Q2 2026
ADAGE CAPITAL PARTNERS GP, L.L.C.Reduced
Hedge Fund
$28.0M· 0.6% of total· 0.0% port· 130K sh· $-44.0M QoQ· Q2 2026
Woodline Partners LPAdded
Hedge Fund
$24.3M· 0.6% of total· 0.1% port· 112K sh· +$741K QoQ· Q2 2026
Hudson Bay Capital Management LPReduced
Hedge Fund
$19.4M· 0.4% of total· 0.1% port· 90K sh· $-24.1M QoQ· Q2 2026
Point72 Asset Management, L.P.Reduced
Hedge Fund
$19.0M· 0.4% of total· 0.0% port· 88K sh· +$18.0M QoQ· Q2 2026
RENAISSANCE TECHNOLOGIES LLCReduced
Hedge Fund
$16.8M· 0.4% of total· 0.0% port· 78K sh· $-27.1M QoQ· Q2 2026
SHAW D E & CO INCAdded
Hedge Fund
$16.1M· 0.4% of total· 0.0% port· 74K sh· +$14.7M QoQ· Q2 2026
FARALLON CAPITAL MANAGEMENT LLCAdded
Hedge Fund
$15.3M· 0.3% of total· 0.1% port· 71K sh· — QoQ· Q2 2026
ORBIMED ADVISORS LLCUnchanged
Hedge Fund
$13.3M· 0.3% of total· 0.2% port· 62K sh· +$0 QoQ· Q2 2026
Verition Fund Management LLCAdded
Hedge Fund
$6.7M· 0.2% of total· 0.0% port· 31K sh· — QoQ· Q2 2026
MARSHALL WACE, LLPReduced
Hedge Fund
$2.7M· 0.1% of total· 0.0% port· 13K sh· +$2.2M QoQ· Q2 2026
Lighthouse Investment Partners, LLCReduced
Hedge Fund
$1.6M· 0.0% of total· 0.0% port· 8K sh· $-5.4M QoQ· Q2 2026
TWO SIGMA INVESTMENTS, LPReduced
Hedge Fund
$1.5M· 0.0% of total· 0.0% port· 7K sh· $-505K QoQ· Q2 2026
Squarepoint Ops LLCReduced
Hedge Fund
$1.5M· 0.0% of total· 0.0% port· 7K sh· +$1.3M QoQ· Q2 2026
Rockefeller Capital Management L.P.Reduced
Hedge Fund
$1.3M· 0.0% of total· 0.0% port· 6K sh· $-3.2M QoQ· Q2 2026
Holocene Advisors, LPUnchanged
Hedge Fund
$1.0M· 0.0% of total· 0.0% port· 5K sh· +$0 QoQ· Q2 2026
Eisler Capital (UK) Ltd.Added
Hedge Fund
$730K· 0.0% of total· 0.0% port· 4K sh· $-1.3M QoQ· Q3 2024
ExodusPoint Capital Management, LPAdded
Hedge Fund
$620K· 0.0% of total· 0.0% port· 3K sh· — QoQ· Q2 2026
TCW GROUP INCAdded
Hedge Fund
$532K· 0.0% of total· 0.0% port· 2K sh· +$27K QoQ· Q2 2026
Parallax Volatility Advisers, L.P.Added
Hedge Fund
$495K· 0.0% of total· 0.0% port· 2K sh· +$130K QoQ· Q2 2026
Fulcrum Asset Management LLPAdded
Hedge Fund
$335K· 0.0% of total· 0.0% port· 2K sh· — QoQ· Q2 2026
Bridgewater Advisors Inc.Added
Hedge Fund
$248K· 0.0% of total· 0.0% port· 1K sh· +$4K QoQ· Q2 2026
Walleye Capital LLCReduced
Hedge Fund
$123K· 0.0% of total· 0.0% port· 569 sh· $-3.9M QoQ· Q2 2026
Ancora Advisors, LLCReduced
Hedge Fund
$8K· 0.0% of total· 0.0% port· 39 sh· $-40K QoQ· Q2 2026
1–10 of 32
1 / 4
Loading recent insider activity…
← Stock ownership