| # | Holder | Shares | Value | % of shares out | Δ QoQ |
|---|---|---|---|---|---|
| 1 | SUVRETTA CAPITAL MANAGEMENT, LLC | 1,153,4961.2M | $144M | 8.06% | ADD 29% |
| 2 | First Light Asset Management, LLC | 980,758980,758 | $122M | 6.85% | ADD 38% |
| 3 | BVF INC/IL | 960,989960,989 | $120M | 6.71% | ADD 9% |
| 4 | Frazier Life Sciences Management, L.P. | 882,400882,400 | $110M | 6.16% | ADD 22% |
| 5 | BlackRock, Inc. | 686,853686,853 | $86M | 4.80% | ADD 23% |
| 6 | JENNISON ASSOCIATES LLC | 640,611640,611 | $80M | 4.48% | ADD 65% |
| 7 | VANGUARD CAPITAL MANAGEMENT LLC | 477,294477,294 | $59M | 3.33% | NEW† |
| 8 | STATE STREET CORP | 458,999458,999 | $57M | 3.21% | ADD 9% |
| 9 | FEDERATED HERMES, INC. | 433,015433,015 | $54M | 3.03% | ADD 18% |
| 10 | PRICE T ROWE ASSOCIATES INC /MD/ | 402,564402,564 | $50M | 2.81% | ADD 9743% |
| 11 | FRONTIER CAPITAL MANAGEMENT CO LLC | 374,035374,035 | $47M | 2.61% | NEW† |
| 12 | Woodline Partners LP | 317,517317,517 | $40M | 2.22% | ADD 6% |
| 13 | Siren, L.L.C. | 257,485257,485 | $32M | 1.80% | ADD 243% |
| 14 | EVENTIDE ASSET MANAGEMENT, LLC | 233,248233,248 | $29M | 1.63% | ADD 129% |
| 15 | ALLIANCEBERNSTEIN L.P. | 262,835262,835 | $28M | 1.84% | TRIM -2% |
| 16 | FMR LLC | 215,808215,808 | $27M | 1.51% | TRIM -7% |
| 17 | MPM BIOIMPACT LLC | 206,404206,404 | $26M | 1.44% | — |
| 18 | GEODE CAPITAL MANAGEMENT, LLC | 205,609205,609 | $26M | 1.44% | ADD 15% |
| 19 | PRIMECAP MANAGEMENT CO/CA/ | 195,030195,030 | $24M | 1.36% | NEW |
| 20 | GOLDMAN SACHS GROUP INC | 194,179194,179 | $24M | 1.36% | ADD 96% |
| 21 | Artisan Partners Limited Partnership | 193,796193,796 | $24M | 1.35% | TRIM -8% |
| 22 | Alyeska Investment Group, L.P. | 179,922179,922 | $22M | 1.26% | NEW |
| 23 | EMERALD ADVISERS, LLC | 161,500161,500 | $20M | 1.13% | NEW |
| 24 | First Turn Management, LLC | 148,093148,093 | $18M | 1.03% | NEW |
| 25 | Avidity Partners Management LP | 140,000140,000 | $18M | 0.98% | ADD 625% |
| 26 | ORBIMED ADVISORS LLC | 134,600134,600 | $17M | 0.94% | NEW |
| 27 | MORGAN STANLEY | 127,987127,987 | $16M | 0.89% | TRIM -42% |
| 28 | EMERALD MUTUAL FUND ADVISERS TRUST | 105,820105,820 | $13M | 0.74% | NEW |
| 29 | UBS Group AG | 104,537104,537 | $13M | 0.73% | ADD 186% |
| 30 | Balyasny Asset Management L.P. | 96,72696,726 | $12M | 0.68% | TRIM -11% |
| 31 | MILLENNIUM MANAGEMENT LLC | 93,64693,646 | $12M | 0.65% | ADD 2591% |
| 32 | VANGUARD PORTFOLIO MANAGEMENT LLC | 90,85890,858 | $11M | 0.63% | NEW |
| 33 | Clio Asset Management LLC | 90,75790,757 | $11M | 0.63% | — |
| 34 | Apis Capital Advisors, LLC | 89,00089,000 | $11M | 0.62% | NEW |
| 35 | Point72 Asset Management, L.P. | 88,16088,160 | $11M | 0.62% | ADD 14% |
| 36 | NEXTBio Capital Management LP | 82,68682,686 | $10M | 0.58% | — |
| 37 | Aberdeen Group plc | 81,08181,081 | $10M | 0.57% | NEW |
| 38 | UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 69,90169,901 | $9M | 0.49% | ADD 47% |
| 39 | AWM Investment Company, Inc. | 69,41669,416 | $9M | 0.48% | — |
| 40 | VANGUARD FIDUCIARY TRUST CO | 64,78364,783 | $8M | 0.45% | NEW |
| 41 | Ikarian Capital, LLC | 64,62664,626 | $8M | 0.45% | NEW |
| 42 | NORTHERN TRUST CORP | 64,37164,371 | $8M | 0.45% | ADD 18% |
| 43 | SEVEN GRAND MANAGERS, LLC | 60,00060,000 | $7M | 0.42% | NEW |
| 44 | Clearbridge Investments, LLC | 59,41059,410 | $7M | 0.42% | TRIM -2% |
| 45 | NEUBERGER BERMAN GROUP LLC | 49,10349,103 | $6M | 0.34% | ADD 9% |
| 46 | Invesco Ltd. | 48,52748,527 | $6M | 0.34% | TRIM -11% |
| 47 | Lisanti Capital Growth, LLC | 41,44541,445 | $5M | 0.29% | — |
| 48 | Ensign Peak Advisors, Inc | 39,22339,223 | $5M | 0.27% | NEW |
| 49 | SAMSARA BIOCAPITAL, LLC | 38,43238,432 | $5M | 0.27% | TRIM -63% |
| 50 | BANK OF AMERICA CORP /DE/ | 37,97237,972 | $5M | 0.27% | ADD 25% |
| 51 | Trexquant Investment LP | 36,63936,639 | $5M | 0.26% | NEW |
| 52 | WCM INVESTMENT MANAGEMENT, LLC | 39,96439,964 | $4M | 0.28% | NEW |
| 53 | WELLINGTON MANAGEMENT GROUP LLP | 34,04034,040 | $4M | 0.24% | ADD 52% |
| 54 | ROYCE & ASSOCIATES LP | 31,50731,507 | $4M | 0.22% | ADD 5% |
| 55 | Blue Owl Capital Holdings LP | 31,25931,259 | $4M | 0.22% | TRIM -22% |
| 56 | Informed Momentum Co LLC | 29,32829,328 | $4M | 0.20% | NEW |
| 57 | BNP PARIBAS FINANCIAL MARKETS | 27,78127,781 | $3M | 0.19% | ADD 5811% |
| 58 | Nicholas Investment Partners, LP | 27,60327,603 | $3M | 0.19% | NEW |
| 59 | RAYMOND JAMES FINANCIAL INC | 25,44625,446 | $3M | 0.18% | ADD 14% |
| 60 | ADAGE CAPITAL PARTNERS GP, L.L.C. | 25,00025,000 | $3M | 0.17% | NEW |
| 61 | NOMURA HOLDINGS INC | 24,00824,008 | $3M | 0.17% | NEW |
| 62 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 22,97022,970 | $3M | 0.16% | ADD 6% |
| 63 | TD Asset Management Inc | 22,74622,746 | $3M | 0.16% | NEW |
| 64 | FRED ALGER MANAGEMENT, LLC | 21,23621,236 | $3M | 0.15% | TRIM -86% |
| 65 | NEW YORK STATE COMMON RETIREMENT FUND | 21,14221,142 | $3M | 0.15% | ADD 22% |
| 66 | Nuveen, LLC | 20,83420,834 | $3M | 0.15% | ADD 6% |
| 67 | CITADEL ADVISORS LLC | 20,47220,472 | $3M | 0.14% | ADD 677% |
| 68 | ExodusPoint Capital Management, LP | 20,27720,277 | $3M | 0.14% | NEW |
| 69 | BlueCrest Capital Management Ltd | 20,00020,000 | $2M | 0.14% | NEW |
| 70 | FIFTH THIRD BANCORP | 19,94719,947 | $2M | 0.14% | NEW |
| 71 | Swiss National Bank | 19,40019,400 | $2M | 0.14% | ADD 37% |
| 72 | BOOTHBAY FUND MANAGEMENT, LLC | 18,96218,962 | $2M | 0.13% | NEW |
| 73 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 18,80818,808 | $2M | 0.13% | NEW |
| 74 | Bank of New York Mellon Corp | 18,04118,041 | $2M | 0.13% | ADD 11% |
| 75 | RENAISSANCE TECHNOLOGIES LLC | 17,97017,970 | $2M | 0.13% | TRIM -20% |
| 76 | MANUFACTURERS LIFE INSURANCE COMPANY, THE | 17,90717,907 | $2M | 0.13% | ADD 689% |
| 77 | SEI INVESTMENTS CO | 16,66316,663 | $2M | 0.12% | ADD 42% |
| 78 | Legato Capital Management LLC | 16,02316,023 | $2M | 0.11% | ADD 41% |
| 79 | Rafferty Asset Management, LLC | 14,59014,590 | $2M | 0.10% | TRIM -7% |
| 80 | F/m Investments LLC | 13,83913,839 | $2M | 0.10% | NEW |
| 81 | Russell Investments Group, Ltd. | 13,52713,527 | $2M | 0.09% | ADD 1001% |
| 82 | Squarepoint Ops LLC | 13,06713,067 | $2M | 0.09% | NEW |
| 83 | Cresset Asset Management, LLC | 11,86011,860 | $1M | 0.08% | ADD 4% |
| 84 | VICTORY CAPITAL MANAGEMENT INC | 11,40311,403 | $1M | 0.08% | TRIM -19% |
| 85 | ALPS ADVISORS INC | 11,13211,132 | $1M | 0.08% | ADD 15% |
| 86 | Calamos Advisors LLC | 9,8049,804 | $1M | 0.07% | NEW |
| 87 | RHUMBLINE ADVISERS | 9,1299,129 | $1M | 0.06% | ADD 6% |
| 88 | Quadrature Capital Ltd | 8,2328,232 | $1M | 0.06% | NEW |
| 89 | DEUTSCHE BANK AG\ | 7,7847,784 | $970,275 | 0.05% | ADD 18% |
| 90 | Knights of Columbus Asset Advisors LLC | 7,7587,758 | $967,035 | 0.05% | NEW |
| 91 | Virtu Financial LLC | 7,7267,726 | $963,000 | 0.05% | NEW |
| 92 | Legal & General Group Plc | 7,4467,446 | $928,144 | 0.05% | ADD 27% |
| 93 | CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM | 6,8956,895 | $859,462 | 0.05% | — |
| 94 | Jump Financial, LLC | 6,7436,743 | $840,515 | 0.05% | NEW |
| 95 | Aquatic Capital Management LLC | 6,6526,652 | $829,172 | 0.05% | NEW |
| 96 | PROFUND ADVISORS LLC | 6,4986,498 | $809,976 | 0.05% | ADD 12% |
| 97 | VANGUARD ASSET MANAGEMENT, Ltd | 6,3996,399 | $797,635 | 0.04% | NEW |
| 98 | Vanguard Global Advisers, LLC | 6,2096,209 | $773,952 | 0.04% | NEW |
| 99 | STATE OF WISCONSIN INVESTMENT BOARD | 5,9295,929 | $739,050 | 0.04% | ADD 31% |
| 100 | HighVista Strategies LLC | 5,9035,903 | $735,809 | 0.04% | NEW |
† 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 |
|---|---|---|---|---|---|---|---|
| SUVRETTA CAPITAL MANAGEMENT, LLC | 714K | 714K | 714K | 822K | 892K | 1.2M | $144M |
| First Light Asset Management, LLC | — | — | — | 542K | 709K | 981K | $122M |
| BVF INC/IL | 697K | 697K | 697K | 1.2M | 879K | 961K | $120M |
| Frazier Life Sciences Management, L.P. | 654K | 690K | 722K | 722K | 722K | 882K | $110M |
| BlackRock, Inc. | 13K | 111K | 445K | 488K | 559K | 687K | $86M |
| JENNISON ASSOCIATES LLC | — | — | — | 107K | 387K | 641K | $80M |
| VANGUARD CAPITAL MANAGEMENT LLC | — | — | — | — | — | 477K | $59M |
| STATE STREET CORP | — | 12K | 82K | 137K | 420K | 459K | $57M |
| FEDERATED HERMES, INC. | — | — | — | 339K | 368K | 433K | $54M |
| PRICE T ROWE ASSOCIATES INC /MD/ | — | — | — | 4K | 4K | 403K | $50M |
| FRONTIER CAPITAL MANAGEMENT CO LLC | — | — | — | — | — | 374K | $47M |
| Woodline Partners LP | — | 194K | 446K | 346K | 301K | 318K | $40M |
| Siren, L.L.C. | — | — | — | — | 75K | 257K | $32M |
| EVENTIDE ASSET MANAGEMENT, LLC | — | — | — | — | 102K | 233K | $29M |
| ALLIANCEBERNSTEIN L.P. | — | — | — | — | 269K | 263K | $28M |
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.
| Quarter | Holders | Shares held | % shares out | Value held |
|---|---|---|---|---|
| 2026-Q1 | 181 | 13,260,061 | 92.6% | $1.6B |
| 2025-Q4 | 140 | 9,759,635 | 82.5% | $1.0B |
| 2025-Q3 | 100 | 8,529,826 | 77.1% | $535M |
| 2025-Q2 | 65 | 5,909,749 | 53.5% | $133M |
| 2025-Q1 | 41 | 5,123,399 | 46.5% | $143M |
| 2024-Q4 | 33 | 4,033,115 | — | $48M |
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.
“Mr. Kaupinen serves as President and Chief Executive Officer of the Issuer and is a member of the board of directors of the Issuer, and, in such capacity, may have influence over the corporate activities of the Issuer, including activities which may relate to items described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. Subject to the Lock-up Agreement described in Item 6 of this Schedule 13D and the Issuer's Insider Trading Policy, each Reporting Persons may from time to time purc”
| Biggest buyers | Δ shares | Δ value | |
|---|---|---|---|
| VANGUARD CAPITAL MANAGEMENT LLC | +477,294 | $59M | OPEN |
| PRICE T ROWE ASSOCIATES INC /MD/ | +398,474 | $50M | ADD |
| FRONTIER CAPITAL MANAGEMENT CO LLC | +374,035 | $47M | OPEN |
| First Light Asset Management, LLC | +271,617 | $34M | ADD |
| SUVRETTA CAPITAL MANAGEMENT, LLC | +261,096 | $33M | ADD |
| Biggest sellers | Δ shares | Δ value | |
|---|---|---|---|
| VANGUARD GROUP INC | −560,616 | $70M | CLOSE |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC | −389,420 | $49M | CLOSE |
| PERCEPTIVE ADVISORS LLC | −266,287 | $33M | CLOSE |
| FRED ALGER MANAGEMENT, LLC | −128,790 | $16M | TRIM |
| MORGAN STANLEY | −92,675 | $12M | TRIM |
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).
| BIOTECHNOLOGY VALUE FUND L P | 7.1% | Passive | 2025-12-31 | SEC → |
| Frazier Life Sciences Public Fund, L.P. | 6% | Passive | 2025-12-31 | SEC → |
| BlackRock, Inc. | 5.7% | QII | 2026-06-30 | 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).
