InvestorLens

BIIB — BIOGEN INC

Health Care

Sign in to save4 tracked investors reported this
For educational research only.InvestorLens analyzes public regulatory filings (SEC EDGAR, STOCK Act PTRs) that may be delayed by 45 days or more. Information shown is historical and is not financial, legal, or tax advice, nor a recommendation or solicitation to buy or sell any security. Always do your own research.

InvestorLens aggregates public filing data to show which tracked investors reported holdings in this stock. Dollar values represent reported position values, not market capitalization, and may be delayed up to 45 days. Not a recommendation.

Sourced from SEC EDGAR public filings

Why are billionaires buying BIIB?

Built from public SEC filings and public economic data. Not a recommendation.

Confidence
50
Institutional Conviction
Net distribution · 2 buying vs 2 selling last quarter
36
Macro Tailwind
Macro conditions are mixed for this sector
58
Congressional Activity
5 congressional purchases, 1 sale disclosed in the last 6 months
Why? — Evidence & Confidence ▾

Of 4 tracked investors who changed their BIIB position last quarter, 2 bought and 2 sold (50% buy-side). Macro conditions are mixed for this sector (Macro Tailwind 58/100 in a Squeeze regime). 5 congressional purchases, 1 sale disclosed in the last 6 months.

Supporting evidence
  • +2 tracked investors added or increased positions last quarter (Ken Griffin, Paul Tudor Jones)
  • +4 tracked investors reported holding BIIB at their latest filing
  • +Macro Health is 55/100 in a Squeeze regime — historically acceptable for Health Caresource
  • +5 congressional purchases disclosed in the last 6 months
Contradicting evidence — always shown
  • −2 tracked investors reduced or exited last quarter (2 reduced, 0 sold out)
  • −13F data is disclosed up to 45 days after quarter end — positions may have changed since
Know the limits
  • · 13F disclosure lag (up to 45 days)
  • · Tracked investors are a sample, not the whole market
  • · Sector regime fit is a historical average, not a guarantee

Every InvestorLens score shows its evidence — including what argues against it. Model conviction-v1 · generated 8/20/2026.

About BIOGEN INC (BIIB)

BIOGEN INC (BIIB) appears in the most recent 13F filings of 4 tracked institutional investors. BIOGEN INC is classified in the Health Care sector. The largest disclosed position is held by Steve Cohen (Point72 Asset Management), valued at $683M. Across recent filings, tracked investors recorded 7 new positions, 12 increased, 15 reduced, and 3 exited. All data sourced from SEC 13F filings.

Smart Money Consensus™

Based on recent institutional activity in BIIB

51
/100
Mixed Activity
Added / Increased19
Reduced15
Exited3
BearishBullish
Crowded Trade Score™

How many top investors track BIIB

27
/100
Emerging Interest
4investors

A small number of top investors own this.

UndiscoveredCrowded
151015+

BIIB Ownership Composition

How BIOGEN INC is held across tracked investor types, based on reported 13F positions.

Dominant Type
Multi-Strategy / Quant
100% of tracked value
Institutions
4
tracked investors
Total Reported
$218.4M
combined 13F value
Types2
  • Multi-Strategy / Quant99.5%
  • Macro0.5%
Multi-Strategy / Quant(3)
99.5%
Macro(1)
0.5%

Tracked investors currently reporting BIIB

1 tracked investor has since exited this position — listed separately below.

  • Steve CohenJun 30, 2026
    Point72 Asset Management
    Shares
    88.7K
    Value
    $19.2M
    % Portfolio
    0.02%
  • Ken GriffinJun 30, 2026
    Citadel Advisors
    Shares
    867.6K
    Value
    $187.4M
    % Portfolio
    0.02%
  • Izzy EnglanderJun 30, 2026
    Millennium Management
    Shares
    49.5K
    Value
    $10.7M
    % Portfolio
    0.00%
  • Paul Tudor JonesJun 30, 2026
    Tudor Investment Corp
    Shares
    4.8K
    Value
    $1M
    % Portfolio
    0.00%

Previously held BIIB

These investors reported BIIB in an earlier quarter but not in their most recent 13F. Figures below are their last reported position, not a current holding.

InvestorFirmLast reported sharesValue thenLast held
Ray DalioBridgewater Associates40K$5.6KSep 30, 2025

Recent activity

Frequently asked questions

How many institutional investors hold BIIB?
4 tracked institutional investors disclosed a position in BIIB (BIOGEN INC) in their most recent 13F filing.
Who is the largest institutional holder of BIIB?
Steve Cohen, Point72 Asset Management, holds the largest disclosed position in BIIB, valued at $683M.
Did institutional ownership of BIIB increase or decrease?
Across recent 13F filings, tracked investors recorded 7 new positions, 12 increased, 15 reduced, and 3 fully exited BIIB.
What sector is BIIB in?
BIOGEN INC is classified in the Health Care GICS sector.
Where does this BIIB ownership data come from?
SEC Form 13F-HR filings, accessed via EDGAR. 13F filings are disclosed quarterly with a 45-day reporting delay and cover U.S.-listed long equity positions only. This is not investment advice.