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 |
|---|---|---|---|---|---|---|---|
| MPM BIOIMPACT LLC | — | — | — | — | — | 4.8M | $87M |
| EcoR1 Capital, LLC | — | — | — | — | — | 4.8M | $86M |
| Blue Owl Capital Holdings LP | — | — | — | — | — | 3.2M | $57M |
| WELLINGTON MANAGEMENT GROUP LLP | — | — | — | — | — | 2.3M | $41M |
| T. Rowe Price Investment Management, Inc. | — | — | — | — | — | 2.1M | $38M |
| BlackRock, Inc. | — | — | — | — | — | 2.1M | $38M |
| RTW INVESTMENTS, LP | — | — | — | — | — | 1.6M | $28M |
| PRICE T ROWE ASSOCIATES INC /MD/ | — | — | — | — | — | 1.6M | $28M |
| RA CAPITAL MANAGEMENT, L.P. | — | — | — | — | — | 1.5M | $27M |
| JANUS HENDERSON GROUP PLC | — | — | — | — | — | 1.5M | $26M |
| BAKER BROS. ADVISORS LP | — | — | — | — | — | 996K | $18M |
| Octagon Capital Advisors LP | — | — | — | — | — | 961K | $17M |
| Avidity Partners Management LP | — | — | — | — | — | 937K | $17M |
| Merck & Co., Inc. | — | — | — | — | — | 953K | $17M |
| VANGUARD CAPITAL MANAGEMENT LLC | — | — | — | — | — | 834K | $15M |
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.
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.
“The MPM Entities acquired the securities reported herein for investment purposes and not with an intent, purpose or effect of changing control of the Issuer. Although the Reporting Persons currently have no plan or proposal to acquire any additional Issuer securities or to dispose of any of the Issuer securities reported herein, the Reporting Persons may, from time to time, acquire additional equity securities or debt securities of the Issuer, which debt securities may be convertible or non-conv”
“The Reporting Person acquired the securities reported herein for investment purposes and intends to continue to review its investments in the Issuer on an ongoing basis. Except as set forth herein, the Reporting Person does not currently have any specific plan or proposal to acquire or dispose of Common Stock of the Issuer or any securities exercisable for or convertible into Common Stock of the Issuer, but the Reporting Person, consistent with its investment purpose, may at any time and from ti”
“The information set forth in Item 3 of this Statement is incorporated herein by reference. The Reporting Persons hold the securities of the Issuer for general investment purposes. The Reporting Persons may, from time to time, depending on prevailing market, economic and other conditions, acquire additional shares of Common Stock or other securities of the Issuer, dispose of any such securities, or engage in discussions with the Issuer concerning such acquisitions or dispositions or further inves”
“Oleg Nodelman, the manager of EcoR1, is a member of the Issuer's board of directors. The reporting persons acquired securities of the Issuer for investment purposes based on their belief that the Issuer's securities represented an attractive investment opportunity. The reporting persons will routinely monitor the Issuer regarding a wide variety of factors that affect their investment considerations, including, current and anticipated future trading prices of the Common Stock and other securities”
| Holder | % of class | Type | As of | |
|---|---|---|---|---|
| Blue Owl Capital Holdings LP | 5.92% | QII | 2026-03-31 | 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).
