BIIB BIOGEN INC.: institutional ownership and insider trading
1,124 funds reported holding $37.5B of BIOGEN INC. in their latest 13F filings; in Q2 2026 funds net bought $1.96B, with 114 new positions and 82 funds selling out; over the last 12 months insiders bought $585 and sold $905K on the open market.
Famous investors holding BIIB
- Ken Griffin (Citadel Advisors): $187M, 0.0% of the portfolio
- Renaissance Technologies (Renaissance Technologies): $16.8M, 0.0% of the portfolio
- D. E. Shaw (D. E. Shaw & Co.): $17.5M, 0.0% of the portfolio
- Izzy Englander (Millennium Management): $10.7M, 0.0% of the portfolio
- Two Sigma (Two Sigma Investments): $1.54M, 0.0% of the portfolio
Largest institutional holders of BIIB
- FMR LLC — $3.94B
- BlackRock, Inc. (BLK) — $3.45B
- PRIMECAP MANAGEMENT CO/CA/ — $3.27B
- VANGUARD GROUP INC — $3.07B
- Banque Cantonale Vaudoise — $2.48B
- VANGUARD CAPITAL MANAGEMENT LLC — $2.09B
- STATE STREET CORP (STT, STT-PG) — $1.59B
- VANGUARD PORTFOLIO MANAGEMENT LLC — $1.43B
- GEODE CAPITAL MANAGEMENT, LLC — $958M
- WELLINGTON MANAGEMENT GROUP LLP — $674M
Recent BIIB insider trades
- Aug 4, 2026: Minor Lloyd sold 1,186 shares ($240K)
- Feb 12, 2026: Murphy Nicole bought 3 shares ($585)
- Feb 9, 2026: Singhal Priya sold 2,660 shares ($532K)
- Feb 2, 2026: Singhal Priya sold 748 shares ($134K)
Members of Congress trading BIIB
- Sep 24, 2026: Maria Elvira Salazar sold part of $1.00K–$15.0K
- Aug 18, 2026: Kevin Hern sold $1.00K–$15.0K
- Jun 5, 2026: Gilbert Ray Cisneros, Jr. bought $1.00K–$15.0K
- Jun 2, 2026: Maria Elvira Salazar sold $15.0K–$50.0K
- May 12, 2026: Maria Elvira Salazar bought $1.00K–$15.0K
- May 11, 2026: Maria Elvira Salazar bought $50.0K–$100K
- May 11, 2026: Maria Elvira Salazar bought $1.00K–$15.0K
- Jan 30, 2026: Gilbert Ray Cisneros, Jr. bought $1.00K–$15.0K
- May 15, 2025: Robert P. Bresnahan, Jr. bought $1.00K–$15.0K
- Apr 8, 2025: Robert P. Bresnahan, Jr. sold $1.00K–$15.0K
5%+ owners
- FMR LLC: 12.4% (Schedule 13G/A, filed Aug 6, 2026)
- Vanguard Capital Management: 7.5% (Schedule 13G, filed Apr 29, 2026)