Institutional holders Insiders (Form 4) Congress
% of shares outstanding held
45.3%
Shares held (13F)
2,619,481
Top holders largest 24 of 24 · Δ vs 2025-Q4 # Holder Shares Value % of shares out Δ QoQ 1 1 Bain Capital Life Sciences Investors, LLC 664,021 664,021 $6M 11.48% TRIM -91% 2 2 GILEAD SCIENCES, INC. 650,389 650,389 $5M 11.25% TRIM -93% 3 3 Frazier Life Sciences Management, L.P. 422,505 422,505 $4M 7.31% TRIM -93% 4 4 Sio Capital Management, LLC 152,464 152,464 $1M 2.64% TRIM -93% 5 5 VANGUARD CAPITAL MANAGEMENT LLC 123,660 123,660 $1M 2.14% NEW † 6 6 Caligan Partners LP 112,128 112,128 $942,996 1.94% NEW 7 7 Merck & Co., Inc. 105,982 105,982 $891,309 1.83% TRIM -93% 8 8 Stonepine Capital Management, LLC 64,162 64,162 $539,602 1.11% TRIM -49% 9 9 MORGAN STANLEY 57,493 57,493 $483,516 0.99% TRIM -93% 10 10 RENAISSANCE TECHNOLOGIES LLC 49,566 49,566 $416,850 0.86% TRIM -86% 11 11 AJU IB Investment Co., Ltd. 47,695 47,695 $401,115 0.82% TRIM -93% 12 12 GEODE CAPITAL MANAGEMENT, LLC 37,197 37,197 $312,848 0.64% TRIM -89% 13 13 FMR LLC 36,558 36,558 $307,453 0.63% TRIM -93% 14 14 VANGUARD FIDUCIARY TRUST CO 28,475 28,475 $239,475 0.49% NEW 15 15 GSA CAPITAL PARTNERS LLP 16,946 16,946 $143,000 0.29% TRIM -89% 16 16 Velan Capital Investment Management LP 14,285 14,285 $120,137 0.25% TRIM -92% 17 17 Ghisallo Capital Management LLC 13,800 13,800 $116,058 0.24% TRIM -99% 18 18 STATE STREET CORP 13,311 13,311 $111,946 0.23% TRIM -93% 19 19 CWM, LLC 4,206 4,206 $35,372 0.07% NEW 20 20 UBS Group AG 4,038 4,038 $33,960 0.07% ADD 1889% 21 21 JPMORGAN CHASE & CO 240 240 $1,976 0.00% NEW 22 22 Vanguard Global Advisers, LLC 210 210 $1,766 0.00% NEW 23 23 ROYAL BANK OF CANADA 91 91 $1,000 0.00% NEW 24 24 Key Financial Inc 59 59 $496 0.00% TRIM -93%
† 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 trends· top 15 holders · shares held over 6 quarters green added · red trimmed6 12 24 Max
Holder 2024-Q4 2025-Q1 2025-Q2 2025-Q3 2025-Q4 2026-Q1 Latest value Bain Capital Life Sciences Investors, LLC 4.6M 4.6M 4.6M 4.6M 7.4M 664K $6M GILEAD SCIENCES, INC. 9.1M 9.1M 9.1M 9.1M 9.1M 650K $5M Frazier Life Sciences Management, L.P. — — — — 5.9M 423K $4M Sio Capital Management, LLC — — — — 2.1M 152K $1M VANGUARD CAPITAL MANAGEMENT LLC — — — — — 124K $1M Caligan Partners LP — — — — — 112K $942,996 Merck & Co., Inc. 1.5M 1.5M 1.5M 1.5M 1.5M 106K $891,309 Stonepine Capital Management, LLC — — — — 126K 64K $539,602 MORGAN STANLEY 1.0M 1.2M 1.4M 962K 840K 57K $483,516 RENAISSANCE TECHNOLOGIES LLC 297K 178K 164K 205K 344K 50K $416,850 AJU IB Investment Co., Ltd. 668K 668K 668K 668K 668K 48K $401,115 GEODE CAPITAL MANAGEMENT, LLC 358K 379K 370K 329K 329K 37K $312,848 FMR LLC 1.4M 884K 512K 512K 512K 37K $307,453 VANGUARD FIDUCIARY TRUST CO — — — — — 28K $239,475 GSA CAPITAL PARTNERS LLP — — — — 148K 17K $143,000
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.
Institutional footprint by quarter reporting 13F holders 42 24 2021-Q4 2026-Q1 2021-Q4 · 42 holders · % suppressed/unavailable 2022-Q1 · 41 holders · % suppressed/unavailable 2022-Q2 · 33 holders · % suppressed/unavailable 2022-Q3 · 29 holders · % suppressed/unavailable 2022-Q4 · 28 holders · % suppressed/unavailable 2023-Q1 · 32 holders · % suppressed/unavailable 2023-Q2 · 32 holders · % suppressed/unavailable 2023-Q3 · 31 holders · % suppressed/unavailable 2023-Q4 · 34 holders · % suppressed/unavailable 2024-Q1 · 31 holders · % suppressed/unavailable 2024-Q2 · 32 holders · % suppressed/unavailable 2024-Q3 · 33 holders · % suppressed/unavailable 2024-Q4 · 35 holders · % suppressed/unavailable 2025-Q1 · 35 holders · % suppressed/unavailable 2025-Q2 · 35 holders · % suppressed/unavailable 2025-Q3 · 36 holders · % suppressed/unavailable 2025-Q4 · 37 holders · % suppressed/unavailable 2026-Q1 · 24 holders · 45.3% of shares out Holder count only — too few computable %-of-shares-outstanding quarters for a % pane. Line breaks are quarters with no 13F record, never interpolated.
Quarter Holders Shares held % shares out Value held 2026-Q1 24 2,619,481 45.3% $22M 2025-Q4 37 39,727,815 — $25M 2025-Q3 36 22,051,916 — $19M 2025-Q2 35 23,795,263 — $16M 2025-Q1 35 22,528,206 — $16M 2024-Q4 35 25,855,355 — $25M 2024-Q3 33 15,953,020 — $13M 2024-Q2 32 14,509,248 — $14M 2024-Q1 31 12,917,723 — $14M 2023-Q4 34 16,556,871 — $9M 2023-Q3 31 15,860,510 — $33M 2023-Q2 32
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.
