| # | Holder | Shares | Value | % of shares out | Δ QoQ |
|---|---|---|---|---|---|
| 1 | EcoR1 Capital, LLC | 22,970,38823.0M | $575M | 31.15% | — |
| 2 | Rubric Capital Management LP | 7,000,0007.0M | $175M | 9.49% | ADD 22% |
| 3 | BlackRock, Inc. | 4,553,8884.6M | $114M | 6.17% | — |
| 4 | BVF INC/IL | 3,734,1423.7M | $94M | 5.06% | TRIM -5% |
| 5 | PERCEPTIVE ADVISORS LLC | 3,510,0783.5M | $88M | 4.76% | ADD 8% |
| 6 | MORGAN STANLEY | 2,480,5682.5M | $62M | 3.36% | TRIM -4% |
| 7 | BNP PARIBAS ASSET MANAGEMENT Holding S.A. | 1,908,0391.9M | $48M | 2.59% | ADD 5% |
| 8 | VANGUARD CAPITAL MANAGEMENT LLC | 1,705,5801.7M | $43M | 2.31% | NEW† |
| 9 | CITADEL ADVISORS LLC | 1,150,0181.2M | $29M | 1.56% | ADD 350% |
| 10 | DIMENSIONAL FUND ADVISORS LP | 1,139,1351.1M | $29M | 1.54% | — |
| 11 | Nextech Invest, Ltd. | 1,113,9461.1M | $28M | 1.51% | — |
| 12 | STATE STREET CORP | 1,011,7771.0M | $25M | 1.37% | TRIM -2% |
| 13 | Capricorn Fund Managers Ltd | 1,007,2101.0M | $25M | 1.37% | — |
| 14 | DEUTSCHE BANK AG\ | 921,250921,250 | $23M | 1.25% | TRIM -42% |
| 15 | ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | 743,898743,898 | $19M | 1.01% | ADD 6% |
| 16 | Assenagon Asset Management S.A. | 727,986727,986 | $18M | 0.99% | ADD 12% |
| 17 | FMR LLC | 667,153667,153 | $17M | 0.90% | ADD 19% |
| 18 | GEODE CAPITAL MANAGEMENT, LLC | 659,940659,940 | $17M | 0.89% | — |
| 19 | Nuveen, LLC | 651,662651,662 | $16M | 0.88% | — |
| 20 | GOLDMAN SACHS GROUP INC | 599,486599,486 | $15M | 0.81% | ADD 43% |
| 21 | MPM BIOIMPACT LLC | 565,249565,249 | $14M | 0.77% | NEW |
| 22 | Prosight Management, LP | 539,049539,049 | $13M | 0.73% | — |
| 23 | Qube Research & Technologies Ltd | 511,937511,937 | $13M | 0.69% | ADD 8% |
| 24 | VANGUARD PORTFOLIO MANAGEMENT LLC | 499,875499,875 | $13M | 0.68% | NEW |
| 25 | Redmile Group, LLC | 491,654491,654 | $12M | 0.67% | — |
| 26 | Hillsdale Investment Management Inc. | 345,622345,622 | $9M | 0.47% | ADD 45% |
| 27 | SummitTX Capital, L.P. | 321,427321,427 | $8M | 0.44% | ADD 43% |
| 28 | NORTHERN TRUST CORP | 320,210320,210 | $8M | 0.43% | ADD 4% |
| 29 | UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 319,385319,385 | $8M | 0.43% | — |
| 30 | ROYCE & ASSOCIATES LP | 299,202299,202 | $7M | 0.41% | NEW |
| 31 | PICTON MAHONEY ASSET MANAGEMENT | 256,690256,690 | $6M | 0.35% | ADD 5% |
| 32 | Granahan Investment Management, LLC | 250,773250,773 | $6M | 0.34% | ADD 12% |
| 33 | HRT FINANCIAL LP | 237,889237,889 | $6M | 0.32% | ADD 96% |
| 34 | BANK OF AMERICA CORP /DE/ | 236,754236,754 | $6M | 0.32% | ADD 164% |
| 35 | D. E. Shaw & Co., Inc. | 235,621235,621 | $6M | 0.32% | ADD 5% |
| 36 | JANE STREET GROUP, LLC | 226,967226,967 | $6M | 0.31% | ADD 222% |
| 37 | PANAGORA ASSET MANAGEMENT INC | 206,854206,854 | $5M | 0.28% | ADD 164% |
| 38 | Man Group plc | 189,890189,890 | $5M | 0.26% | ADD 152% |
| 39 | WELLS FARGO & COMPANY/MN | 189,636189,636 | $5M | 0.26% | TRIM -9% |
| 40 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 185,124185,124 | $5M | 0.25% | TRIM -16% |
| 41 | FEDERATED HERMES, INC. | 182,410182,410 | $5M | 0.25% | ADD 19% |
| 42 | RAYMOND JAMES FINANCIAL INC | 176,411176,411 | $4M | 0.24% | TRIM -6% |
| 43 | UBS Group AG | 171,779171,779 | $4M | 0.23% | TRIM -38% |
| 44 | SILVERCREST ASSET MANAGEMENT GROUP LLC | 163,649163,649 | $4M | 0.22% | TRIM -10% |
| 45 | KENNEDY CAPITAL MANAGEMENT LLC | 148,226148,226 | $4M | 0.20% | — |
| 46 | XTX Topco Ltd | 143,882143,882 | $4M | 0.20% | ADD 54% |
| 47 | DIADEMA PARTNERS LP | 142,132142,132 | $4M | 0.19% | NEW |
| 48 | WELLINGTON MANAGEMENT GROUP LLP | 138,690138,690 | $3M | 0.19% | TRIM -24% |
| 49 | Invesco Ltd. | 125,630125,630 | $3M | 0.17% | TRIM -51% |
| 50 | Bank of New York Mellon Corp | 124,105124,105 | $3M | 0.17% | TRIM -3% |
| 51 | CITIGROUP INC | 114,327114,327 | $3M | 0.16% | ADD 3% |
| 52 | JPMORGAN CHASE & CO | 114,072114,072 | $3M | 0.15% | ADD 226% |
| 53 | PLATINUM INVESTMENT MANAGEMENT LTD | 105,184105,184 | $3M | 0.14% | — |
| 54 | Tidal Investments LLC | 104,931104,931 | $3M | 0.14% | NEW |
| 55 | Tema ETFs LLC | 104,931104,931 | $3M | 0.14% | ADD 38% |
| 56 | Fisher Asset Management, LLC | 101,439101,439 | $3M | 0.14% | ADD 49% |
| 57 | Susquehanna Portfolio Strategies, LLC | 99,79599,795 | $2M | 0.14% | — |
| 58 | AQR CAPITAL MANAGEMENT LLC | 90,66990,669 | $2M | 0.12% | — |
| 59 | KORNITZER CAPITAL MANAGEMENT INC /KS | 88,80088,800 | $2M | 0.12% | — |
| 60 | VANGUARD FIDUCIARY TRUST CO | 84,40384,403 | $2M | 0.11% | NEW |
| 61 | Squarepoint Ops LLC | 83,14683,146 | $2M | 0.11% | NEW |
| 62 | MACKENZIE FINANCIAL CORP | 82,72682,726 | $2M | 0.11% | ADD 82% |
| 63 | Verdad Advisers, LP | 82,69882,698 | $2M | 0.11% | NEW |
| 64 | PRINCIPAL FINANCIAL GROUP INC | 78,54778,547 | $2M | 0.11% | NEW |
| 65 | FRANKLIN RESOURCES INC | 77,65977,659 | $2M | 0.11% | ADD 32% |
| 66 | STIFEL FINANCIAL CORP | 76,75676,756 | $2M | 0.10% | — |
| 67 | RHUMBLINE ADVISERS | 75,39975,399 | $2M | 0.10% | — |
| 68 | CREDIT AGRICOLE S A | 75,00075,000 | $2M | 0.10% | — |
| 69 | AMERIPRISE FINANCIAL INC | 74,22274,222 | $2M | 0.10% | TRIM -34% |
| 70 | Swiss National Bank | 74,20074,200 | $2M | 0.10% | — |
| 71 | AMERICAN CENTURY COMPANIES INC | 70,85170,851 | $2M | 0.10% | ADD 20% |
| 72 | STATE OF WISCONSIN INVESTMENT BOARD | 66,10666,106 | $2M | 0.09% | TRIM -13% |
| 73 | ALLIANCEBERNSTEIN L.P. | 55,89655,896 | $1M | 0.08% | ADD 12% |
| 74 | Dana Investment Advisors, Inc. | 56,10756,107 | $1M | 0.08% | ADD 16% |
| 75 | Campbell & CO Investment Adviser LLC | 54,88354,883 | $1M | 0.07% | ADD 63% |
| 76 | Russell Investments Group, Ltd. | 47,45047,450 | $1M | 0.06% | TRIM -19% |
| 77 | ROYAL BANK OF CANADA | 47,36047,360 | $1M | 0.06% | TRIM -14% |
| 78 | SEGALL BRYANT & HAMILL, LLC | 45,72645,726 | $1M | 0.06% | NEW |
| 79 | North Growth Management Ltd. | 46,00046,000 | $1M | 0.06% | ADD 2% |
| 80 | JACOBS LEVY EQUITY MANAGEMENT, INC | 42,78642,786 | $1M | 0.06% | NEW |
| 81 | VICTORY CAPITAL MANAGEMENT INC | 42,40442,404 | $1M | 0.06% | — |
| 82 | ENVESTNET ASSET MANAGEMENT INC | 40,41940,419 | $1M | 0.05% | — |
| 83 | Manatuck Hill Partners, LLC | 40,00040,000 | $1M | 0.05% | NEW |
| 84 | LOS ANGELES CAPITAL MANAGEMENT LLC | 39,75039,750 | $995,338 | 0.05% | ADD 10171% |
| 85 | Quantinno Capital Management LP | 39,64039,640 | $992,586 | 0.05% | ADD 37% |
| 86 | Zurcher Kantonalbank (Zurich Cantonalbank) | 39,35539,355 | $985,449 | 0.05% | ADD 93% |
| 87 | Connor, Clark & Lunn Investment Management Ltd. | 37,91937,919 | $949,492 | 0.05% | NEW |
| 88 | HSBC HOLDINGS PLC | 37,77737,777 | $940,079 | 0.05% | ADD 6% |
| 89 | CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM | 37,38937,389 | $936,221 | 0.05% | — |
| 90 | O'SHAUGHNESSY ASSET MANAGEMENT, LLC | 37,12937,129 | $929,710 | 0.05% | TRIM -14% |
| 91 | TUDOR INVESTMENT CORP ET AL | 36,87536,875 | $923,350 | 0.05% | ADD 22% |
| 92 | HighTower Advisors, LLC | 36,26236,262 | $908,000 | 0.05% | NEW |
| 93 | Persistent Asset Partners Ltd | 35,93535,935 | $899,812 | 0.05% | ADD 389% |
| 94 | PRICE T ROWE ASSOCIATES INC /MD/ | 35,48735,487 | $889,000 | 0.05% | ADD 23% |
| 95 | HighVista Strategies LLC | 34,08534,085 | $853,488 | 0.05% | NEW |
| 96 | Vinva Investment Management Ltd | 24,09024,090 | $850,787 | 0.03% | ADD 97% |
| 97 | MARTINGALE ASSET MANAGEMENT L P | 32,76432,764 | $820,411 | 0.04% | NEW |
| 98 | Creative Planning | 32,39432,394 | $811,146 | 0.04% | ADD 14% |
| 99 | MARSHALL WACE, LLP | 32,22332,223 | $806,863 | 0.04% | NEW |
| 100 | MANUFACTURERS LIFE INSURANCE COMPANY, THE | 31,59231,592 | $791,064 | 0.04% | ADD 81% |
† a filer this large appearing as NEW usually reflects a renamed or succeeded filing entity (the old name stops filing the same quarter) — not a brand-new position.
Rows rank by the value each filer reported — 13F filers price their own positions, so a holder with fewer shares can rank just above one with more.
| Holder | 2024-Q4 | 2025-Q1 | 2025-Q2 | 2025-Q3 | 2025-Q4 | 2026-Q1 | Latest value |
|---|---|---|---|---|---|---|---|
| EcoR1 Capital, LLC | 15.0M | 17.3M | 23.0M | 23.0M | 23.0M | 23.0M | $575M |
| Rubric Capital Management LP | 3.9M | 4.3M | 4.7M | 4.7M | 5.8M | 7.0M | $175M |
| BlackRock, Inc. | 4.2M | 4.1M | 3.8M | 4.0M | 4.6M | 4.6M | $114M |
| BVF INC/IL | 4.3M | 4.3M | 4.3M | 3.9M | 3.9M | 3.7M | $94M |
| PERCEPTIVE ADVISORS LLC | 2.1M | 1.9M | 1.3M | 2.1M | 3.3M | 3.5M | $88M |
| MORGAN STANLEY | 4.2M | 4.1M | 4.2M | 4.0M | 2.6M | 2.5M | $62M |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. | 2.1M | 2.2M | 2.0M | — | 1.8M | 1.9M | $48M |
| VANGUARD CAPITAL MANAGEMENT LLC | — | — | — | — | — | 1.7M | $43M |
| CITADEL ADVISORS LLC | 58K | 181K | 246K | 207K | 255K | 1.2M | $29M |
| DIMENSIONAL FUND ADVISORS LP | 973K | 1.1M | 1.2M | 1.2M | 1.2M | 1.1M | $29M |
| Nextech Invest, Ltd. | — | 1.1M | 1.1M | 1.1M | 1.1M | 1.1M | $28M |
| STATE STREET CORP | 1.1M | 1.1M | 1.1M | 1.1M | 1.0M | 1.0M | $25M |
| Capricorn Fund Managers Ltd | — | — | — | — | 1.0M | 1.0M | $25M |
| DEUTSCHE BANK AG\ | 1.5M | 1.6M | 1.5M | 1.5M | 1.6M | 921K | $23M |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | — | — | — | 314K | 700K | 744K | $19M |
Shares reported each quarter by the largest current holders. Green = added vs the prior filing, red = trimmed, grey = roughly held; a dash is a quarter with no 13F on file (a gap is skipped, not read as an exit). 13F is filed up to 45 days after quarter-end. Up to 40 quarters (10 years) available — use the selector above.
Line breaks are honest gaps — quarters with no 13F record, or a suppressed % — never interpolated. % of shares outstanding divides each quarter's as-filed 13F shares by the SEC cover-page share count dated to that same quarter (split-adjusted), not by today's count — so splits and buybacks don't move the line.
Short interest has its own tab now — open SI →
Source: SEC Form 13F — every institution manager (≥ $100M in 13F securities) reporting a long US-listed position, across ~10,250 filers over 10 years of history. 13F is long-only, US-listed, filed up to 45 days after quarter-end.
“Scott Platshon, one of EcoR1's employees, resigned from the Issuer's board of directors as of November 16, 2025. Concurrently with his resignation, Mr. Platshon was appointed as the Issuer's Acting Chief Investment Officer. Oleg Nodelman, the manager of EcoR1, is a member of the Issuer's board of directors. The reporting persons acquired the Stock for investment purposes based on their belief that the Issuer's Common Stock, when purchased, was undervalued and represented an attractive investment”
| Biggest buyers | Δ shares | Δ value | |
|---|---|---|---|
| VANGUARD CAPITAL MANAGEMENT LLC | +1,705,580 | $43M | OPEN |
| Rubric Capital Management LP | +1,250,000 | $31M | ADD |
| CITADEL ADVISORS LLC | +894,667 | $22M | ADD |
| MPM BIOIMPACT LLC | +565,249 | $14M | OPEN |
| VANGUARD PORTFOLIO MANAGEMENT LLC | +499,875 | $13M | OPEN |
| Biggest sellers | Δ shares | Δ value | |
|---|---|---|---|
| VANGUARD GROUP INC | −2,328,727 | $58M | CLOSE |
| Siren, L.L.C. | −1,680,121 | $42M | CLOSE |
| Vestal Point Capital, LP | −865,000 | $22M | CLOSE |
| DEUTSCHE BANK AG\ | −674,583 | $17M | TRIM |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | −663,546 | $17M | CLOSE |
The 2025-Q4 register is as-filed in ITS OWN share basis; every count below was rebased into the 2026-Q1 basis (no split in between, factor 1). Dollar figures value the SHARE delta at one price — the 2026-03-31 close — rather than differencing two filings' own reported values, which would mix the quarter's price move into the trade figure.
13Fs disclose LONG US-listed positions only — shorts, most derivatives, bonds and non-US listings are invisible here, and a filer's quarter-over-quarter change is not necessarily a trade (index rebalances, in-kind transfers and entity successions all read as flow).
| Quarter | Holders | Shares held | % shares out | Value held |
|---|---|---|---|---|
| 2026-Q1 | 211 | 70,281,379 | 95.3% | $1.8B |
| 2025-Q4 | 209 | 71,482,935 | 95.5% | $1.9B |
| 2025-Q3 | 183 | 73,738,024 | 98.1% | $1.3B |
| 2025-Q2 | 181 | 75,689,891 | 108.6% | $950M |
| 2025-Q1 | 185 | 70,606,816 | 101.5% | $841M |
| 2024-Q4 | 173 | 66,481,117 | 96.5% | $973M |
| 2024-Q3 | 163 | 66,616,573 | 93.8% | $835M |
| 2024-Q2 | 164 | 68,263,184 | 96.5% | $581M |
| 2024-Q1 | 171 | 78,335,375 | — | $824M |
| 2023-Q4 | 157 | 69,796,233 | 99.7% | $725M |
| 2023-Q3 | 139 | 62,349,147 | 91.9% | $395M |
| 2023-Q2 | 137 | 63,418,731 | 98.8% | $548M |
| 2023-Q1 | 115 | 56,709,288 | 88.6% | $513M |
| 2022-Q4 | 96 | 57,230,974 | 90.8% | $450M |
| 2022-Q3 | 91 | 47,762,961 | 75.8% | $294M |
| 2022-Q2 | 113 | 47,689,433 | — | $253M |
| 2022-Q1 | 120 | 49,969,954 | — | $327M |
| 2021-Q4 | 114 | 46,167,514 | — | $757M |
| 2021-Q3 | 123 | 36,848,775 | — | $1.1B |
| 2021-Q2 | 109 | 38,836,170 | — | $1.3B |
| 2021-Q1 | 125 | 35,201,795 | — | $1.1B |
| 2020-Q4 | 138 | 34,789,892 | — | $1.6B |
| 2020-Q3 | 127 | 34,866,167 | — | $1.6B |
| 2020-Q2 | 133 | 34,417,859 | — | $1.2B |
| 2020-Q1 | 116 | 33,093,427 | — | $1.2B |
| 2019-Q4 | 103 | 23,790,109 | — | $1.1B |
| 2019-Q3 | 74 | 20,208,398 | — | $499M |
| 2019-Q2 | 67 | 19,705,828 | — | $434M |
| 2019-Q1 | 47 | 11,444,263 | — | $184M |
| 2018-Q4 | 43 | 9,085,831 | — | $132M |
| 2018-Q3 | 46 | 8,363,019 | — | $131M |
| 2018-Q2 | 43 | 8,054,585 | — | $118M |
| 2018-Q1 | 15 | 2,076,050 | — | $26M |
| 2017-Q4 | 15 | 1,850,051 | — | $14M |
| 2017-Q3 | 12 | 1,851,829 | — | $15M |
| 2017-Q2 | 14 | 2,151,305 | — | $18M |
| BIOTECHNOLOGY VALUE FUND L P | 5.2% | Passive | 2025-09-30 | SEC → |
| Redmile Group, LLC | 4.9% | QII | 2025-09-30 | SEC → |
| BlackRock, Inc. | 4.8% | QII | 2025-06-30 | SEC → |
Source: SEC Schedule 13D/13G structured XML. 13D = active intent; 13G filers report passively (Rule 13d-1(b) QII / 13d-1(c) Passive / 13d-1(d) Exempt) and are not activists. Percent and delta are the group aggregate the filing reports. Structured 13D/G coverage begins December 2024 (SEC XML mandate).
