Data from public SEC 13F & STOCK Act filings, delayed up to ~45 days, partial holdings only — for research, not investment advice.
BIIB
BIOGEN INCData as of 2026 Q1 (03-31) · 13F snapshot
Summary
BIOGEN INC (BIIB) is held by 12 tracked hedge-fund managers, a combined reported value of ~$853.32M; the largest are Carl Icahn, Warren Buffett, Steven Cohen. This quarter: 2 added, 3 trimmed. 20 members of Congress have disclosed STOCK Act trades. Data as of 2026 Q1, from public SEC 13F filings, delayed up to ~45 days.
Attention · HighThis quarter · Mixed
Gurus holding12
Congress trades20
Price$200.05vs quarter-end+9.12%
Sectors1
This quarter's moves
Top holderCarl IcahnNew0
Added2
Trimmed / sold3
Carl IcahnHold
Value $235.95M3.5% of portfolio3,215,0512011 Q1
Warren BuffettHold
Value $179.88M0.1% of portfolio643,0222021 Q1
Value $54.98M— of portfolio299,9002026 Q1
Value $27.53M— of portfolio79,4932021 Q2
Value $19.05M— of portfolio103,9002026 Q1
Value $16.99M— of portfolio92,7002026 Q1
Value $15.38M— of portfolio83,9002026 Q1
Michael BurryNew large stake
Value $3.01M2.9% of portfolio10,0002018 Q4
Value $861.7K— of portfolio4,7002026 Q1
| Investor | Value | % of portfolio | Action |
|---|---|---|---|
| Carl Icahn | $235.95M | 3.5% | Hold |
| Warren Buffett | $179.88M | 0.1% | Hold |
| Ken GriffinCALL | $54.98M | — | — |
| Bill Miller | $27.53M | — | — |
| Izzy EnglanderPUT | $19.05M | — | — |
| Ken GriffinPUT | $16.99M | — | — |
| Izzy EnglanderCALL | $15.38M | — | — |
| Michael Burry | $3.01M | 2.9% | New large stake |
| Steven CohenCALL | $861.7K | — | — |