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
In plain English: 11 of the investors we track own this stock. In the latest quarter, 5 of them bought more of it and 7 sold some or all of theirs (1 bought it for the first time). That tells you what they did last quarter — not what the stock will do next.
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
Managers holding
11
-1 vs last quarter (like-for-like)
Total value held
$1.37B
Across tracked managers
Average weight ⓘOn average, how big this stock is in the portfolios that own it (its share of each manager's reported portfolio value).
0.2%
Of each manager's book
QoQ value ⓘLike-for-like: only managers that filed both quarters are compared, so a manager filing late (or confidentially) does not look like buying or selling. Includes price changes.
-$40.37M
-4.7% vs last quarter
Net shares bought
-894.1K
Est. net flow -$188.19M
Quarter activity
5 bought · 7 sold
1 new · 2 sold out
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
Column filters
| Politician | Date | Ticker | Asset | Type | Reported range ⓘThe dollar range the politician reported. Exact amounts are not disclosed. | Est. size ⓘOur estimate only: the midpoint of the reported range. | Owner | Account ⓘSubholding Of: the account the trade was in, as named on the report (e.g. an IRA or a brokerage account). The same stock bought on the same day in different accounts is a separate trade in each account. | Filed ↓ | Filing delay ⓘDays between the trade and the report. Over 45 days is late under the STOCK Act. | Source |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Maria Elvira Salazar Politician | Sep 24, 2026 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Sale (partial) | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | UBS IRA Account | Oct 7, 2026 | 13 days | PTR ↗ |
| Kevin Hern Politician | Aug 18, 2026 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Sale | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | Kevin Hern Traditional IRA | Sep 1, 2026 | 14 days | PTR ↗ |
| Maria Elvira Salazar Politician | Jun 2, 2026 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Sale | $15,001 - $50,000 | Est. $32,500 (midpoint of reported range $15,001–$50,000) | Self | UBS Brokerage Account | Jul 7, 2026 | 35 days | PTR ↗ |
| Gil Cisneros Politician | Jun 5, 2026 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | 150 Main Street Trust > Bank of America | Jul 2, 2026 | 27 days | PTR ↗ |
| Ro Khanna Politician | May 27, 2026 | BIIB | BIOGEN INC. CMN scanned | Sale | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Spouse | — | Jun 9, 2026 | 13 days | PTR ↗ |
| Maria Elvira Salazar Politician | May 11, 2026 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | UBS Brokerage Account | Jun 8, 2026 | 28 days | PTR ↗ |
| Maria Elvira Salazar Politician | May 12, 2026 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | UBS Brokerage Account | Jun 8, 2026 | 27 days | PTR ↗ |
| Maria Elvira Salazar Politician | May 11, 2026 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Purchase | $50,001 - $100,000 | Est. $75,000 (midpoint of reported range $50,001–$100,000) | Self | UBS IRA Account | Jun 8, 2026 | 28 days | PTR ↗ |
| Ro Khanna Politician | Apr 13, 2026 | BIIB | BIOGEN INC. CMN scanned | Sale | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Spouse | — | May 11, 2026 | 28 days | PTR ↗ |
| Gil Cisneros Politician | Jan 30, 2026 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | 150 Main Street Trust > Bank of America | Feb 13, 2026 | 14 days | PTR ↗ |
| Ro Khanna Politician | Jan 29, 2026 | BIIB | BIOGEN INC.CMN scanned | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Spouse | — | Feb 6, 2026 | 8 days | PTR ↗ |
| Ro Khanna Politician | Aug 26, 2025 | BIIB | BIOGEN INC. CMN scanned | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Sep 9, 2025 | 14 days | PTR ↗ |
| Ro Khanna Politician | May 29, 2025 | BIIB | BIOGEN INC. CMN a scanned | Sale (partial) | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Jun 10, 2025 | 12 days | PTR ↗ |
| Robert P. Bresnahan, Jr. Politician | May 15, 2025 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | JP Morgan Brokerage Account | Jun 9, 2025 | 25 days | PTR ↗ |
| Robert P. Bresnahan, Jr. Politician | Apr 8, 2025 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Sale | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | JP Morgan Brokerage Account | May 8, 2025 | 30 days | PTR ↗ |
| Robert P. Bresnahan, Jr. Politician | Feb 25, 2025 | BIIB | Biogen Inc. - Common Stock (BIIB) [ST] | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Self | JP Morgan Brokerage Account | Mar 27, 2025 | 30 days | PTR ↗ |
| Ro Khanna Politician | Feb 25, 2025 | BIIB | BIOGEN INC. CMIN scanned | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Mar 6, 2025 | 9 days | PTR ↗ |
| Ro Khanna Politician | Feb 19, 2025 | BIIB | BIOGEN INC. CMN scanned | Sale | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Mar 6, 2025 | 15 days | PTR ↗ |
| Ro Khanna Politician | Jan 17, 2025 | BIIB | BIOGEN INC. CMN scanned | Sale (partial) | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Feb 6, 2025 | 20 days | PTR ↗ |
| Ro Khanna Politician | Dec 18, 2024 | BIIB | BIOGEN INC. CMN scanned | Sale | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Jan 8, 2025 | 21 days | PTR ↗ |
| Ro Khanna Politician | Dec 16, 2024 | BIIB | BIOGEN INC. CMN scanned | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Jan 8, 2025 | 23 days | PTR ↗ |
| Ro Khanna Politician | Nov 15, 2024 | BIIB | BIOGEN INC. CMN scanned | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Dec 5, 2024 | 20 days | PTR ↗ |
| Ro Khanna Politician | Oct 14, 2024 | BIIB | BIOGEN INC. CMN scanned | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Child | — | Nov 8, 2024 | 25 days | PTR ↗ |
| Ro Khanna Politician | Aug 5, 2024 | BIIB | BIOGEN INC. CMN scanned | Sale (partial) | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | — | — | Sep 6, 2024 | 32 days | PTR ↗ |
| Ro Khanna Politician | Aug 2, 2024 | BIIB | BIOGEN INC. CMIN scanned | Purchase | $1,001 - $15,000 | Est. $8,000 (midpoint of reported range $1,001–$15,000) | Spouse | — | Sep 6, 2024 | 35 days | PTR ↗ |