🕵️ Biogen Inc. ($BIIB)
SEC insider & ownership activity, last 12 months · CIK 875045 · every row links its SEC filing
Over the last 12 months insiders sold $735K against $585 of open-market buying. Singhal Priya sold $735K through a 10b5-1 trading plan in 3 lots (Sep–Feb). No red-flag 8-Ks in the window.
Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
1 buyer, $585 (1 lots) · 1 seller, $735K (3 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Singhal Priya | 0 | – | 3 | $735K | Feb 9, 2026 |
| Murphy Nicole | 1 | $585 | 0 | – | Feb 12, 2026 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| FMR LLC | 11.3% | 13G | Jun 5, 2026 | filing ↗ | |
| Abigail P. Johnson | 11.3% | 13G | Jun 5, 2026 | filing ↗ | |
| Primecap Management CO/CA/ | 10.2% | 13G | Nov 13, 2025 | filing ↗ | |
| Blackrock, Inc. | 8.5% | 13G | Apr 17, 2025 | filing ↗ | |
| Vanguard Capital Management | 7.5% | 13G | Apr 29, 2026 | filing ↗ | |
| State Street Corporation | 5.0% | 13G | Nov 10, 2025 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| Singhal Priya | $532K | Feb 9, 2026 | filing ↗ |
| Singhal Priya | $134K | Feb 2, 2026 | filing ↗ |
| Singhal Priya | $69K | Sep 2, 2025 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Earnings (2.02) | Jul 29, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jul 29, 2026 | filing ↗ |
| Earnings (2.02) | Jul 1, 2026 | filing ↗ |
| Shareholder vote (5.07) | Jun 9, 2026 | filing ↗ |
| Material agreement (1.01) | May 14, 2026 | filing ↗ |
| Acquisition or disposition (2.01) | May 14, 2026 | filing ↗ |
| New financial obligation (2.03) | May 14, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | May 14, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 14, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 14, 2026 | filing ↗ |
| Earnings (2.02) | Apr 29, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Apr 29, 2026 | filing ↗ |
| Earnings (2.02) | Apr 6, 2026 | filing ↗ |
| Material agreement (1.01) | Mar 31, 2026 | filing ↗ |
| Other events (8.01) | Mar 31, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 31, 2026 | filing ↗ |
| Officer/director changes (5.02) | Mar 11, 2026 | filing ↗ |
| Officer/director changes (5.02) | Feb 11, 2026 | filing ↗ |
| Other events (8.01) | Feb 11, 2026 | filing ↗ |
| Earnings (2.02) | Feb 6, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 6, 2026 | filing ↗ |
| Earnings (2.02) | Jan 13, 2026 | filing ↗ |
| Earnings (2.02) | Oct 30, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Oct 30, 2025 | filing ↗ |
| Earnings (2.02) | Oct 14, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Oct 14, 2025 | filing ↗ |
| Earnings (2.02) | Jul 31, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jul 31, 2025 | filing ↗ |