Biogen Inc
Held by 11 tracked managers as of Q2 2026 · CUSIP ⓘCUSIP: A 9-character ID for one specific security - one share class of one company, or one bond. Tickers can change and can mean different things in different countries; a CUSIP always identifies exactly the same security, which is why filings use it. Guide 09062X103 · Sector ⓘGICS sectors: The 11-sector system most investors know (Global Industry Classification Standard): Technology, Health Care, Financials and so on. This site assigns each company a GICS-style sector from its SIC code, with a few hand corrections, so sector pages match the names investors expect. Guide
Educational and informational only, not personalized investment advice. Based on public filings that may be delayed or contain errors; verify with the original filings. Disclaimer
Tracked capital in this stock
Total value held (area) and number of managers (line). Dips can mean a large holder filed that quarter confidentially (e.g. Norges Bank in Q1/Q3).
Aggregate buying and selling
Net share change reported each quarter
Who owns BIIB?
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Who owns BIIB? — Q2 2026
Holders ranked by position size, with each one's quarter-over-quarter change.
Column filters
| # | Manager | Fund | Shares | Value ↓ | % of their portfolio | QoQ | Δ shares | Δ shares % | Est. Δ value ⓘChange in shares × this quarter's price |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Norges Bank | Norges Bank Investment Management | 2.58M | $557.44M | 0.1% | — | — | — | — |
| 2 | Boston Partners | Boston Partners Global Investors | 1.26M | $272.85M | 0.2% | Reduced | -436.6K | -25.7% | -$94.30M |
| 3 | Fred Alger | Fred Alger Management | 788.31K | $170.32M | 0.6% | Added | +55.1K | +7.5% | +$11.91M |
| 4 | LSV Asset Management | LSV Asset Management | 444.05K | $95.94M | 0.2% | Added | +110.3K | +33.1% | +$23.83M |
| 5 | Ken Griffin | Citadel Advisors | 418.36K | $90.39M | 0.1% | Added | +280.3K | +203.0% | +$60.55M |
| 6 | Ken Fisher | Fisher Asset Management | 338.02K | $73.03M | 0.0% | Added | +25.4K | +8.1% | +$5.49M |
| 7 | Causeway | Causeway Capital Management | 278.28K | $60.13M | 0.7% | Reduced | -2.5K | -0.9% | -$540.15K |
| 8 | Steve Cohen | Point72 Asset Management | 88.15K | $19.05M | 0.0% | Reduced | -721.5K | -89.1% | -$155.88M |
| 9 | Jim Simons | Renaissance Technologies | 77.74K | $16.80M | 0.0% | Reduced | -125.7K | -61.8% | -$27.15M |
| 10 | David Shaw | D.E. Shaw & Co. | 74.44K | $16.08M | 0.0% | New | +74.4K | — | +$16.08M |
| 11 | Two Sigma | Two Sigma Investments | 7.11K | $1.54M | 0.0% | Reduced | -2.3K | -24.8% | -$505.36K |
Column filters
| Manager | Fund | Shares sold | Value last quarter ↓ |
|---|---|---|---|
| Israel Englander | Millennium Management | -94.0K | $17.23M |
| Larry Robbins | Glenview Capital | -57.0K | $10.45M |
Politician trades
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No politician trades match these filters.