Who owns BIIB
Institutions that file 13Fs hold 96% of the shares
Shares they hold, quarter on quarter
+5.4%
126 new, 395 added, 269 cut, 97 sold out
Top 10 holders
60%
of the shares institutions hold
A 13F lists the long positions of managers with more than $100M in US stocks. It shows the last day of a quarter and is filed up to 45 days later. Two managers can report the same shares, so totals can count some shares twice.
Institutional owners
The 25 biggest holders
| Holder | Shares | Value | % of company | From Mar 31, 2026 |
|---|---|---|---|---|
| FMR LLC | 18.22M | $3.9B | 12.32% | Added +42.2% |
| BlackRock, Inc. | 15.99M | $3.5B | 10.81% | Held |
| PRIMECAP MANAGEMENT CO/CA/ | 15.15M | $3.3B | 10.25% | Added +2.7% |
| VANGUARD CAPITAL MANAGEMENT LLC | 9.65M | $2.1B | 6.53% | Added +1.2% |
| STATE STREET CORP | 7.34M | $1.6B | 4.97% | Added +2.5% |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 6.60M | $1.4B | 4.47% | Added +1.1% |
| GEODE CAPITAL MANAGEMENT, LLC | 4.45M | $957.9M | 3.01% | Added +2.5% |
| WELLINGTON MANAGEMENT GROUP LLP | 3.12M | $673.6M | 2.11% | Added +5.3% |
| NORGES BANK | 2.58M | $557.4M | 1.75% | New |
| MORGAN STANLEY | 2.41M | $521.0M | 1.63% | Added +11.1% |
| AQR CAPITAL MANAGEMENT LLC | 1.94M | $416.9M | 1.31% | Added +0.7% |
| JPMORGAN CHASE & CO | 1.82M | $394.9M | 1.23% | Reduced -9.6% |
| Invesco Ltd. | 1.80M | $389.8M | 1.22% | Added +3.4% |
| Amundi | 1.52M | $327.7M | 1.03% | Added +91.8% |
| Legal & General Group Plc | 1.49M | $322.6M | 1.01% | Added +10.6% |
| NORTHERN TRUST CORP | 1.43M | $308.9M | 0.97% | Reduced -1.2% |
| Boston Partners | 1.26M | $272.8M | 0.85% | Reduced -25.7% |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 1.26M | $271.2M | 0.85% | Reduced -8.9% |
| GOLDMAN SACHS GROUP INC | 1.23M | $265.8M | 0.83% | Added +17.1% |
| DIMENSIONAL FUND ADVISORS LP | 1.15M | $248.2M | 0.78% | Added +6.4% |
| Pacer Advisors, Inc. | 1.12M | $243K | 0.76% | Added +70.0% |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 1.12M | $241.5M | 0.76% | Reduced -2.8% |
| BANK OF AMERICA CORP /DE/ | 1.12M | $241.2M | 0.76% | Reduced -3.5% |
| UBS Group AG | 1.03M | $222.6M | 0.70% | Added +96.8% |
| Alyeska Investment Group, L.P. | 932K | $201.4M | 0.63% | Added +15.8% |
Show the other 15 holders
This quarter
Who bought and who sold the most shares
Bought the most shares
- FMR LLC +5.41M
- NORGES BANK +2.58M, new
- Amundi +726K
- UBS Group AG +507K
- Pacer Advisors, Inc. +463K
- PRIMECAP MANAGEMENT CO/CA/ +397K
- CITADEL ADVISORS LLC +280K
- PERCEPTIVE ADVISORS LLC +276K, new
- MORGAN STANLEY +240K
- CITIGROUP INC +234K
Sold the most shares
- T. Rowe Price Investment Management, Inc. -1.05M
- VAN ECK ASSOCIATES CORP -982K
- Point72 Asset Management, L.P. -721K
- Boston Partners -437K
- Balyasny Asset Management L.P. -385K
- BARCLAYS PLC -304K
- Sofinnova Investments, Inc. -230K, sold out
- MARSHALL WACE, LLP -217K
- Qube Research & Technologies Ltd -213K, sold out
- ADAGE CAPITAL PARTNERS GP, L.L.C. -204K
Superinvestors
Superinvestors holding BIIB
None of the followed investors held BIIB in their latest 13F.
More than 5%
13D filings: owners who may push for change
No Schedule 13D about BIIB in the last year.