NASDAQ · BIIB
Biogen Inc.
Smart money pulse
What insiders and funds are doing
- account_balance473 funds bought, 328 sold in the quarter ended Jun 30, 2026. 131 were new holders.
- infoNo real insider sales in 12 months. Planned 10b5-1 sales and tax withholding are left out.
−100 means everyone selling, +100 everyone buying. This is data, not advice.
How the Pulse works
Pulse runs from −100 (everyone selling) to +100 (everyone buying). Half comes from insiders: real buyers vs. real sellers in the last 90 days (Form 4). Half comes from funds: funds that bought vs. funds that sold last quarter (13F). 13F is a snapshot of long positions on the last day of the quarter, filed up to 45 days later. It does not show short positions or trades since then.
Who owns it
1,046 funds report owning BIIB, up from 1,014
Last quarter
Who bought and who sold
Change in shares held, biggest holdings first. Bars stop at ±100%.
Insider trades · last 12 months
Real buys and sales
No open-market buys or sales by officers or directors in the last 12 months. Hidden: 1 tax withholding, 1 option exercise. Press All filings to see them.
Last 6 months. A wider screen shows 12.
Showing 0 real trades. Hidden: 1 tax withholding, 1 option exercise. Those happen on a schedule and say little about what an insider thinks. Bigger dot means a bigger trade.
Showing every filing. Dashed circles are routine: grants, tax withholding, option exercises and planned sales.
Congress · last 12 months
Members of Congress who traded BIIB
1 older trade in the last 12 months not shown.
Amounts are the ranges members report, not exact amounts. Reports can come up to 45 days after the trade. From House and Senate STOCK Act reports. This is data, not advice.
Top holders
Biggest funds in BIIB
| Fund | Value | Change |
|---|---|---|
| FMR LLC | $3.94B | +42% |
| BlackRock, Inc. | $3.45B | Same |
| Primecap Management Co | $3.27B | +3% |
| Vanguard Capital Management LLC | $2.09B | +1% |
| State Street Corp | $1.59B | +2% |