Security record · archived quarter
BIIB
Biogen Inc. · Healthcare · Drug Manufacturers - General
163Tracked holders
-1Δ holders
110.78MShares held
$20.30BReported value
+4New positions
−6Exits
Momentum inputs (comparable managers):
holder breadth -0.6% ·
share flow -1.7% ·
net new positions -1.2%
— formula
Broad distribution — falling shares and fewer holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q1 2026
Ownership over time
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q2 2026 | 161 | 0 | 119.37M | $25.78B | +6 | −5 |
| Q1 2026 | 163 | -1 | 110.78M | $20.30B | +4 | −6 |
| Q4 2025 | 163 | 0 | 123.15M | $21.67B | +2 | −1 |
| Q3 2025 | 24 | +1 | 81.72M | $11.44B | +1 | −1 |
| Q2 2025 | 21 | 0 | 78.50M | $9.86B | — | — |
| Q1 2025 | 18 | +2 | 41.87M | $5.73B | +3 | −1 |
| Q4 2024 | 16 | -1 | 41.64M | $6.37B | — | −1 |
| Q3 2024 | 16 | +2 | 32.39M | $6.28B | +2 | — |
| Q2 2024 | 14 | — | 30.72M | $7.12B | — | — |
Who holds it · Q1 2026
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | BlackRock ✦ (passive) | 15.97M | +7.8% | $2.93B | 0.1% | ▲ Add | 4 | SEC ↗ ×21 |
| 2 | PRIMECAP Management ✦ | 14.76M | 0.0% | $2.71B | 2.1% | ▼ Trim | 8 | SEC ↗ |
| 3 | Fidelity (FMR) ✦ | 12.81M | +35.9% | $2.35B | 0.1% | ▲ Add | 4 | SEC ↗ ×7 |
| 4 | Vanguard Capital Management Llc | 9.54M | — | $1.75B | 0.0% | n/c | 1 | SEC ↗ |
| 5 | State Street Global Advisors ✦ (passive) | 7.17M | +0.1% | $1.31B | 0.0% | ▲ Add | 6 | SEC ↗ |
| 6 | Geode Capital Management ✦ (passive) | 4.34M | +3.4% | $793.39M | 0.0% | ▲ Add | 8 | SEC ↗ ×2 |
| 7 | Wellington Management ✦ | 2.96M | -16.6% | $542.96M | 0.1% | ▼ Trim | 8 | SEC ↗ ×5 |
| 8 | Morgan Stanley ✦ | 2.17M | -6.6% | $398.00M | 0.0% | ▼ Trim | 3 | SEC ↗ ×16 |
| 9 | JPMorgan Chase ✦ | 2.02M | +8.6% | $378.14M | 0.0% | ▲ Add | 3 | SEC ↗ ×19 |
| 10 | AQR Capital Management ✦ | 1.92M | +25.8% | $346.24M | 0.2% | ▲ Add | 8 | SEC ↗ ×10 |
| 11 | Invesco Ltd. | 1.75M | +5.4% | $319.96M | 0.0% | ▲ Add | 2 | SEC ↗ ×21 |
| 12 | Boston Partners | 1.70M | -1.2% | $311.66M | 0.3% | ▼ Trim | 2 | SEC ↗ ×4 |
| 13 | Northern Trust Corp | 1.45M | 0.0% | $265.20M | 0.0% | ▲ Add | 2 | SEC ↗ ×9 |
| 14 | UBS AM, a distinct business unit of… | 1.38M | -1.0% | $252.55M | 0.1% | ▼ Trim | 2 | SEC ↗ ×11 |
| 15 | Legal & General Group Plc | 1.35M | -7.5% | $247.46M | 0.1% | ▼ Trim | 2 | SEC ↗ ×3 |
| 16 | Bank Of America Corp /De/ | 1.16M | +2.4% | $212.00M | 0.0% | ▲ Add | 2 | SEC ↗ ×8 |
| 17 | Charles Schwab Investment… | 1.15M | +0.5% | $210.72M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 18 | Dimensional Fund Advisors Lp | 1.08M | +12.3% | $197.88M | 0.0% | ▲ Add | 2 | SEC ↗ ×5 |
| 19 | Deutsche Bank Ag\ | 1.06M | +11.5% | $195.03M | 0.1% | ▲ Add | 2 | SEC ↗ ×12 |
| 20 | Goldman Sachs Group ✦ | 1.05M | -4.4% | $192.70M | 0.0% | ▼ Trim | 3 | SEC ↗ ×3 |
| 21 | Pictet Asset Management Holding SA | 913.33K | -3.6% | $168.27M | 0.2% | ▼ Trim | 2 | SEC ↗ |
| 22 | Point72 Asset Management ✦ | 809.62K | -71.2% | $148.43M | 0.3% | ▼ Trim | 5 | SEC ↗ |
| 23 | Alyeska Investment Group, L.P. | 805.05K | -21.4% | $147.59M | 0.4% | ▼ Trim | 2 | SEC ↗ |
| 24 | Amundi | 790.83K | +38.1% | $144.98M | 0.0% | ▲ Add | 2 | SEC ↗ ×4 |
| 25 | Bank of New York Mellon Corp | 788.52K | -2.8% | $144.56M | 0.0% | ▼ Trim | 2 | SEC ↗ ×19 |
| 26 | Robeco Institutional Asset… | 763.17K | +24.9% | $139.91M | 0.2% | ▲ Add | 2 | SEC ↗ |
| 27 | Massachusetts Financial Services Co… | 720.63K | +1.1% | $133.70M | 0.0% | ▲ Add | 2 | SEC ↗ ×7 |
| 28 | First Trust Advisors Lp | 673.96K | +19.1% | $123.56M | 0.1% | ▲ Add | 2 | SEC ↗ |
| 29 | T. Rowe Price ✦ | 672.43K | -15.1% | $123.28M | 0.0% | ▼ Trim | 8 | SEC ↗ ×2 |
| 30 | Pacer Advisors, Inc. | 660.41K | -42.4% | $121.07M | 0.3% | ▼ Trim | 2 | SEC ↗ |
| 31 | Balyasny Asset Management L.P. | 650.05K | +6.9% | $119.17M | 0.2% | ▲ Add | 2 | SEC ↗ |
| 32 | Barclays Plc | 551.47K | -57.7% | $101.10M | 0.0% | ▼ Trim | 2 | SEC ↗ ×3 |
| 33 | Royal Bank Of Canada | 531.38K | -1.9% | $97.42M | 0.0% | ▼ Trim | 2 | SEC ↗ ×8 |
| 34 | UBS Group AG | 523.45K | -18.4% | $95.96M | 0.0% | ▼ Trim | 2 | SEC ↗ ×7 |
| 35 | Zurcher Kantonalbank (Zurich… | 522.15K | +15.4% | $95.73M | 0.2% | ▲ Add | 2 | SEC ↗ |
| 36 | Caisse De Depot Et Placement Du… | 518.69K | -11.9% | $95.09M | 0.2% | ▼ Trim | 2 | SEC ↗ |
| 37 | Citigroup Inc | 500.51K | -12.8% | $91.76M | 0.1% | ▼ Trim | 2 | SEC ↗ ×3 |
| 38 | Bnp Paribas Financial Markets | 471.07K | -7.3% | $86.36M | 0.1% | ▼ Trim | 2 | SEC ↗ |
| 39 | Hsbc Holdings Plc | 463.65K | -54.0% | $84.62M | 0.1% | ▼ Trim | 2 | SEC ↗ ×7 |
| 40 | Swiss National Bank | 430.60K | +7.2% | $78.94M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 41 | National Pension Service | 401.67K | +39.8% | $73.64M | 0.1% | ▲ Add | 2 | SEC ↗ |
| 42 | Nuveen, LLC | 358.84K | -4.5% | $65.79M | 0.0% | ▼ Trim | 2 | SEC ↗ ×3 |
| 43 | Sumitomo Mitsui Trust Group, Inc. | 356.29K | -3.9% | $65.32M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 44 | California Public Employees… | 340.90K | +3.0% | $62.50M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 45 | Mitsubishi UFJ Asset Management… | 334.41K | +4.5% | $61.31M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 46 | Adage Capital Partners ✦ | 333.46K | +13.3% | $61.13M | 0.1% | ▲ Add | 5 | SEC ↗ |
| 47 | Victory Capital Management Inc | 320.79K | +30.1% | $58.81M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 48 | Man Group plc | 318.75K | -6.0% | $58.44M | 0.1% | ▼ Trim | 2 | SEC ↗ ×2 |
| 49 | FIL Ltd | 318.06K | -0.5% | $58.31M | 0.0% | ▼ Trim | 2 | SEC ↗ ×2 |
| 50 | Fisher Asset Management ✦ | 312.62K | +6.6% | $57.31M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 51 | Gotham Asset Management ✦ | 298.44K | +7.8% | $54.71M | 0.2% | ▲ Add | 8 | SEC ↗ |
| 52 | Swedbank AB | 289.84K | +25.1% | $53.14M | 0.1% | ▲ Add | 2 | SEC ↗ ×2 |
| 53 | Rhumbline Advisers | 275.44K | +1.4% | $50.50M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 54 | Marshall Wace ✦ | 229.88K | -40.4% | $42.14M | 0.0% | ▼ Trim | 7 | SEC ↗ ×3 |
| 55 | California State Teachers… | 220.69K | -2.5% | $40.46M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 56 | BNP Paribas Asset Management… | 215.44K | -12.3% | $39.51M | 0.0% | ▼ Trim | 2 | SEC ↗ ×3 |
| 57 | Qube Research & Technologies Ltd | 212.92K | New | $39.03M | 0.1% | New | 1 | SEC ↗ |
| 58 | Alliancebernstein L.P. | 212.90K | +15.9% | $37.47M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 59 | Renaissance Technologies ✦ | 203.40K | -49.0% | $37.29M | 0.1% | ▼ Trim | 8 | SEC ↗ |
| 60 | Principal Financial Group Inc | 187.06K | +1.6% | $34.29M | 0.0% | ▲ Add | 2 | SEC ↗ ×2 |
| 61 | Allianz Asset Management GmbH | 178.05K | -28.1% | $32.64M | 0.0% | ▼ Trim | 2 | SEC ↗ ×3 |
| 62 | Prudential Financial Inc | 163.89K | -53.6% | $30.05M | 0.0% | ▼ Trim | 2 | SEC ↗ ×2 |
| 63 | Aberdeen Group plc | 151.14K | +8.1% | $27.71M | 0.0% | ▲ Add | 2 | SEC ↗ ×2 |
| 64 | Franklin Resources Inc | 144.45K | +2.2% | $26.48M | 0.0% | ▲ Add | 2 | SEC ↗ ×8 |
| 65 | Susquehanna International Group, Llp | 140.30K | -78.8% | $25.72M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 66 | Citadel Advisors ✦ | 138.09K | +241.6% | $25.32M | 0.0% | ▲ Add | 7 | SEC ↗ ×2 |
| 67 | Russell Investments Group, Ltd. | 135.84K | +14.1% | $25.08M | 0.0% | ▲ Add | 2 | SEC ↗ ×10 |
| 68 | Ameriprise Financial Inc | 132.60K | +0.6% | $24.31M | 0.0% | ▲ Add | 2 | SEC ↗ ×4 |
| 69 | Td Asset Management Inc | 127.27K | -6.0% | $23.33M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 70 | Wells Fargo & Company/Mn | 127.13K | +6.5% | $23.31M | 0.0% | ▲ Add | 2 | SEC ↗ ×5 |
| 71 | State Board Of Administration Of… | 124.21K | -1.2% | $22.77M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 72 | Creative Planning | 117.24K | +30.3% | $21.49M | 0.0% | ▲ Add | 2 | SEC ↗ ×2 |
| 73 | Quantinno Capital Management LP | 116.37K | +18.4% | $21.34M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 74 | LMR Partners LLP | 116.13K | +1245.7% | $21.29M | 0.2% | ▲ Add | 2 | SEC ↗ ×2 |
| 75 | Canada Pension Plan Investment Board | 114.94K | -16.8% | $21.07M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 76 | American Century Companies Inc | 104.78K | +22.1% | $19.21M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 77 | New York State Common Retirement… | 99.84K | +0.6% | $18.30M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 78 | Walleye Trading LLC | 99.53K | +4.2% | $18.25M | 0.4% | ▲ Add | 2 | SEC ↗ |
| 79 | Federated Hermes, Inc. | 97.28K | -25.8% | $17.83M | 0.0% | ▼ Trim | 2 | SEC ↗ ×3 |
| 80 | Aviva Plc | 96.86K | -22.4% | $17.76M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 81 | Raymond James Financial Inc | 96.70K | +15.5% | $17.73M | 0.0% | ▲ Add | 2 | SEC ↗ ×3 |
| 82 | Manufacturers Life Insurance… | 95.11K | -10.1% | $17.44M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 83 | Millennium Management ✦ | 93.96K | -91.7% | $17.23M | 0.0% | ▼ Trim | 8 | SEC ↗ |
| 84 | Bank Of Montreal /Can/ | 92.71K | -18.4% | $17.00M | 0.0% | ▼ Trim | 2 | SEC ↗ ×7 |
| 85 | LPL Financial LLC | 81.72K | -8.7% | $14.98M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 86 | National Bank Of Canada /Fi/ | 78.88K | -18.3% | $14.46M | 0.0% | ▼ Trim | 2 | SEC ↗ ×4 |
| 87 | State Of Wisconsin Investment Board | 78.56K | +3.5% | $14.40M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 88 | Cerity Partners LLC | 76.64K | +12.1% | $14.05M | 0.0% | ▲ Add | 2 | SEC ↗ ×3 |
| 89 | Korea Investment CORP | 73.99K | +37.2% | $13.56M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 90 | Chevy Chase Trust Holdings, LLC | 72.64K | -2.8% | $13.32M | 0.0% | ▼ Trim | 2 | SEC ↗ ×2 |
| 91 | Mariner, LLC | 72.04K | +37.3% | $13.21M | 0.0% | ▲ Add | 2 | SEC ↗ ×3 |
| 92 | Sei Investments Co | 71.51K | +20.2% | $13.11M | 0.0% | ▲ Add | 2 | SEC ↗ ×2 |
| 93 | Mackenzie Financial Corp | 71.43K | +0.5% | $13.10M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 94 | Universal- Beteiligungs- und… | 68.24K | -44.9% | $12.55M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 95 | Mitsubishi UFJ Trust & Banking Corp | 65.09K | -0.3% | $11.93M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 96 | Envestnet Asset Management Inc | 64.69K | +10.0% | $11.86M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 97 | Royal London Asset Management Ltd | 64.27K | -0.5% | $11.78M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 98 | Asset Management One Co., Ltd. | 64.10K | -5.0% | $11.75M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 99 | Nomura Asset Management Co Ltd | 62.98K | -6.5% | $11.55M | 0.0% | ▼ Trim | 2 | SEC ↗ ×2 |
| 100 | MIRAE ASSET GLOBAL ETFS HOLDINGS… | 60.78K | +5.1% | $11.15M | 0.0% | ▲ Add | 2 | SEC ↗ ×3 |
“Their weight” = the position's share of that manager's reported 13F equity value — the conviction measure. ✦ = curated manager.
New buyers
| Qube Research & Technologies… | $39.03M | 0.1% |
Exited
| Norges Bank | $464.41M | was 0.1% |
| Hrt Financial Lp | $67.63M | was 0.2% |
| D. E. Shaw & Co. | $9.46M | was 0.0% |
| Arrowstreet Capital | $7.98M | was 0.0% |
| IMC-Chicago, LLC | $3.35M | was 0.1% |
| Capstone Investment Advisors… | $430,296 | was 0.0% |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 995 holders, 132.27M shares, $23.30B reported. This is a different, older period than the tracked-universe figures above and the two are never mixed.
Frequently co-owned
What else this security's tracked holders most often hold — shared-ownership counts, not fundamental relationships.
Aug 06
SC 13G/A — FMR LLC
Jun 05
SC 13G/A — FMR LLC
Provenance: Ownership from parsed 13F common-stock positions (tracked universe, comparable sets for changes); insider rows from Forms 3/4/5; stakes from Schedules 13D/13G; every filing links to its original on SEC EDGAR.
Reporting period: Q1 2026 ·
Methodology ·
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