BIIB Biogen Inc.
Biogen Inc. (BIIB) Institutional Ownership
What the institutions did with BIIB last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.
Every manager below opens. Subscribers can see any firm's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.
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Each block is one manager, sized by shares held and colored by how much they moved the position last quarter. Green added, red cut, grey stood pat.
Largest holders
| Manager | Shares | % of reported |
|---|---|---|
| FMR LLC | 18.2M | 12.8% |
| BlackRock, Inc. | 16.0M | 11.2% |
| PRIMECAP MANAGEMENT CO/CA/ | 15.2M | 10.7% |
| VANGUARD CAPITAL MANAGEMENT LLC | 9.7M | 6.8% |
| STATE STREET CORP | 7.3M | 5.2% |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 6.6M | 4.6% |
| GEODE CAPITAL MANAGEMENT, LLC | 4.4M | 3.1% |
| WELLINGTON MANAGEMENT GROUP LLP | 3.1M | 2.2% |
| NORGES BANK | 2.6M | 1.8% |
| MORGAN STANLEY | 2.4M | 1.7% |
| AQR CAPITAL MANAGEMENT LLC | 1.9M | 1.4% |
| JPMORGAN CHASE & CO | 1.8M | 1.3% |
| Invesco Ltd. | 1.8M | 1.3% |
| Amundi | 1.5M | 1.1% |
| Legal & General Group Plc | 1.5M | 1.0% |
| NORTHERN TRUST CORP | 1.4M | 1.0% |
| Boston Partners | 1.3M | 0.9% |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 1.3M | 0.9% |
| GOLDMAN SACHS GROUP INC | 1.2M | 0.9% |
| DIMENSIONAL FUND ADVISORS LP | 1.1M | 0.8% |
| Pacer Advisors, Inc. | 1.1M | 0.8% |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 1.1M | 0.8% |
| BANK OF AMERICA CORP /DE/ | 1.1M | 0.8% |
| UBS Group AG | 1.0M | 0.7% |
| Alyeska Investment Group, L.P. | 932.4K | 0.7% |
Largest changes
| Manager | Action | Previous | Current | Change |
|---|---|---|---|---|
| FMR LLC | Increased | 12.8M | 18.2M | +5.4M |
| T. Rowe Price Investment Management, Inc. | Reduced | 1.2M | 113.9K | -1.0M |
| VAN ECK ASSOCIATES CORP | Reduced | 1.1M | 98.1K | -981.8K |
| Amundi | Increased | 790.8K | 1.5M | +726.0K |
| Point72 Asset Management, L.P. | Reduced | 809.6K | 88.1K | -721.5K |
| UBS Group AG | Increased | 523.5K | 1.0M | +506.7K |
| Pacer Advisors, Inc. | Increased | 660.4K | 1.1M | +462.6K |
| Boston Partners | Reduced | 1.7M | 1.3M | -436.6K |
| PRIMECAP MANAGEMENT CO/CA/ | Increased | 14.8M | 15.2M | +397.0K |
| Balyasny Asset Management L.P. | Reduced | 650.0K | 265.1K | -385.0K |
| BARCLAYS PLC | Reduced | 551.5K | 247.2K | -304.3K |
| CITADEL ADVISORS LLC | Increased | 138.1K | 418.4K | +280.3K |
| PERCEPTIVE ADVISORS LLC | New | 0 | 276.2K | +276.2K |
| MORGAN STANLEY | Increased | 2.2M | 2.4M | +240.3K |
| CITIGROUP INC | Increased | 500.5K | 734.5K | +234.0K |
| Sofinnova Investments, Inc. | Sold Out | 229.5K | 0 | -229.5K |
| MARSHALL WACE, LLP | Reduced | 229.9K | 12.6K | -217.3K |
| Qube Research & Technologies Ltd | Sold Out | 212.9K | 0 | -212.9K |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | 333.5K | 129.6K | -203.9K |
| Logos Global Management LP | Sold Out | 200.0K | 0 | -200.0K |
| JPMORGAN CHASE & CO | Reduced | 2.0M | 1.8M | -192.9K |
| VOYA INVESTMENT MANAGEMENT LLC | Increased | 54.6K | 246.8K | +192.2K |
| GOLDMAN SACHS GROUP INC | Increased | 1.1M | 1.2M | +179.3K |
| ROYAL BANK OF CANADA | Increased | 531.4K | 708.6K | +177.2K |
| STATE STREET CORP | Increased | 7.2M | 7.3M | +176.4K |
| SG Americas Securities, LLC | Reduced | 195.7K | 22.8K | -172.9K |
| DEUTSCHE BANK AG\ | Reduced | 1.1M | 894.0K | -169.8K |
| WELLINGTON MANAGEMENT GROUP LLP | Increased | 3.0M | 3.1M | +155.8K |
| NISSAY ASSET MANAGEMENT CORP /JAPAN | Increased | 29.8K | 185.3K | +155.5K |
| JUPITER ASSET MANAGEMENT LTD | Increased | 7.1K | 160.1K | +152.9K |
| ExodusPoint Capital Management, LP | Reduced | 152.0K | 2.9K | -149.1K |
| Legal & General Group Plc | Increased | 1.3M | 1.5M | +143.5K |
| LORD, ABBETT & CO. LLC | New | 0 | 130.2K | +130.2K |
| Alyeska Investment Group, L.P. | Increased | 805.1K | 932.4K | +127.3K |
| RENAISSANCE TECHNOLOGIES LLC | Reduced | 203.4K | 77.7K | -125.7K |
| Man Group plc | Reduced | 318.7K | 196.2K | -122.5K |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | Reduced | 1.4M | 1.3M | -122.4K |
| ACADIAN ASSET MANAGEMENT LLC | Reduced | 248.5K | 129.9K | -118.6K |
| THOMPSON SIEGEL & WALMSLEY LLC | Reduced | 248.3K | 130.5K | -117.8K |
| VANGUARD CAPITAL MANAGEMENT LLC | Increased | 9.5M | 9.7M | +113.7K |
| Hudson Bay Capital Management LP | Reduced | 201.4K | 90.0K | -111.4K |
| LMR Partners LLP | Reduced | 116.1K | 4.9K | -111.3K |
| LSV ASSET MANAGEMENT | Increased | 333.7K | 444.0K | +110.3K |
| GEODE CAPITAL MANAGEMENT, LLC | Increased | 4.3M | 4.4M | +106.7K |
| Nippon Life Global Investors Americas, Inc. | Increased | 33.6K | 137.2K | +103.7K |
| PRICE T ROWE ASSOCIATES INC /MD/ | Increased | 672.4K | 774.3K | +101.9K |
| CANADA PENSION PLAN INVESTMENT BOARD | Reduced | 114.9K | 13.6K | -101.3K |
| Defilade Capital Management, L.P. | Sold Out | 96.3K | 0 | -96.3K |
| Patient Capital Management, LLC | Reduced | 379.7K | 283.7K | -96.0K |
| MILLENNIUM MANAGEMENT LLC | Sold Out | 94.0K | 0 | -94.0K |
| PRUDENTIAL FINANCIAL INC | Reduced | 163.9K | 72.3K | -91.5K |
| STRS OHIO | Increased | 3.5K | 93.8K | +90.3K |
| ANTIPODES PARTNERS Ltd | New | 0 | 86.8K | +86.8K |
| Freestone Grove Partners LP | New | 0 | 83.9K | +83.9K |
| BNP PARIBAS FINANCIAL MARKETS | Reduced | 471.1K | 387.5K | -83.5K |
| D. E. Shaw & Co., Inc. | New | 0 | 74.4K | +74.4K |
| Treasurer of the State of North Carolina | Increased | 75.2K | 148.6K | +73.5K |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Increased | 6.5M | 6.6M | +73.2K |
| FARALLON CAPITAL MANAGEMENT LLC | New | 0 | 71.0K | +71.0K |
| TD Asset Management Inc | Reduced | 127.3K | 57.8K | -69.5K |
13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.