AI Holders Summary · Q2 2026

148 institutions reported SION in Q2 2026. RA CAPITAL MANAGEMENT, L.P. leads at 24.8% of the visible book.

Top holders

Sorted by position value. Source: SEC EDGAR 13F-HR filings.

Hide index funds / market makers / custodians(2 on this page)

#HolderValueShares% port.Quarter

RA CAPITAL MANAGEMENT, L.P.

CIK 0001346824

$436M9.9M3.79%Q2 2026 02

TPG GP A, LLC

CIK 0001903793

$260M6.5M7.08%Q1 2026 03

Atlas Venture Life Science Advisors, LLC

CIK 0001917529

$132M3.0M14.95%Q2 2026 04

VIKING GLOBAL INVESTORS LP

CIK 0001103804

$128M3.2M0.36%Q1 2026 05

ORBIMED ADVISORS LLC

CIK 0001055951

$112M2.6M2.10%Q2 2026 06

Enavate Sciences GP, LLC

CIK 0001953107

$109M2.5M31.56%Q2 2026 07

ADAGE CAPITAL PARTNERS GP, L.L.C.

CIK 0001165408

$70M1.6M0.10%Q2 2026 08

BlackRock, Inc.

CIK 0002012383

$65M1.5M0.00%Q2 2026 09

JPMORGAN CHASE & CO

CIK 0000019617

$64M1.5M0.00%Q2 2026 10

JENNISON ASSOCIATES LLC

CIK 0000053417

$52M1.2M0.03%Q2 2026 11

CITADEL ADVISORS LLC

CIK 0001423053

$51M1.2M0.01%Q2 2026 12

VANGUARD CAPITAL MANAGEMENT LLC

CIK 0002100119· Index

$50M1.1M0.00%Q2 2026 13

STATE STREET CORP

CIK 0000093751

$45M1.0M0.00%Q2 2026 14

DEERFIELD MANAGEMENT COMPANY, L.P.

CIK 0001009258

$40M971K0.51%Q4 2025 15

PRICE T ROWE ASSOCIATES INC /MD/

CIK 0000080255

$30M756K0.00%Q1 2026 16

Siren, L.L.C.

CIK 0002005245

$27M611K0.54%Q2 2026 17

PERCEPTIVE ADVISORS LLC

CIK 0001224962

$26M658K0.52%Q1 2026 18

EVENTIDE ASSET MANAGEMENT, LLC

CIK 0001442891

$21M475K0.28%Q2 2026 19

GEODE CAPITAL MANAGEMENT, LLC

CIK 0001214717· Index

$20M457K0.00%Q2 2026 20

Casdin Capital, LLC

CIK 0001534261

$18M400K0.88%Q2 2026

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