Biogen Inc. (BIIB)
Healthcare
Drug Manufacturers - General
203.00 $
-2.4%
vs. previous close
Closing price · As of: 31. Jul 2026
Who owns Biogen Inc. (BIIB)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 99.7% of the shares are freely tradable; institutional investors hold 96.4%.
Ownership Structure
Institutional ownership
Share of the stock held by institutional investors (funds, banks, insurers) according to regulatory filings.
96.4%
Insiders
Share of the stock held by the executives, founders and major shareholders of the company itself.
0.2%
Float
Share of stock freely tradable on the market — not locked up in the hands of founders, insiders, or major shareholders.
99.7%
Short % of float
Shares sold short as a percentage of the freely tradable float — high values signal many bets on falling prices.
4.5%
Shares Outstanding
Total number of shares issued. Price times share count gives market cap.
148Mio.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 10.81 | 15,974,601 | +7.9 | 03/31/2026 |
| PRIMECAP Management Company | 9.99 | 14,757,607 | +0.0 | 03/31/2026 |
| FMR Inc | 8.67 | 12,807,541 | +35.9 | 03/31/2026 |
| Vanguard Capital Management, LLC | 6.45 | 9,537,417 | +0.0 | 03/31/2026 |
| State Street Corp | 4.85 | 7,167,922 | +0.1 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 4.42 | 6,531,727 | +0.0 | 03/31/2026 |
| Geode Capital Management, LLC | 2.94 | 4,342,602 | +3.4 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard PRIMECAP Inv | 5.66 | 8,359,880 | +0.0 | 03/31/2026 |
| Fidelity Contrafund | 3.38 | 4,988,655 | +22.4 | 06/30/2026 |
| Vanguard Morn Total Stk Mkt Idx Investor | 3.17 | 4,688,827 | +0.4 | 06/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Data as of: July 31, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.