SION Sionna Therapeutics, Inc.: institutional ownership and insider trading
160 funds reported holding $2.17B of Sionna Therapeutics, Inc. in their latest 13F filings; in Q2 2026 funds net bought $127M, with 36 new positions and 8 funds selling out; over the last 12 months insiders bought $0 and sold $154M on the open market.
Famous investors holding SION
- Andreas Halvorsen (Viking Global Investors): $141M, 0.4% of the portfolio
- Ken Griffin (Citadel Advisors): $50.9M, 0.0% of the portfolio
- Izzy Englander (Millennium Management): $14.3M, 0.0% of the portfolio
- D. E. Shaw (D. E. Shaw & Co.): $4.47M, 0.0% of the portfolio
Largest institutional holders of SION
- RA CAPITAL MANAGEMENT, L.P. — $436M
- TPG GP A, LLC — $286M
- VIKING GLOBAL INVESTORS LP — $141M
- Atlas Venture Life Science Advisors, LLC — $132M
- ORBIMED ADVISORS LLC — $112M
- Enavate Sciences GP, LLC — $109M
- ADAGE CAPITAL PARTNERS GP, L.L.C. — $70.4M
- BlackRock, Inc. (BLK) — $64.9M
- JPMORGAN CHASE & CO (JPM, AMJB, VYLD, JPM-PC, JPM-PD, JPM-PJ, JPM-PK, JPM-PL, JPM-PM) — $64.1M
- JENNISON ASSOCIATES LLC — $51.6M
Recent SION insider trades
- Sep 17, 2026: RA Capital Healthcare Fund LP sold 3,448,811 shares ($21.8M)
- Jul 7, 2026: Orbimed Advisors Llc sold 85,918 shares ($3.85M)
- Jul 7, 2026: Thompson Peter A. sold 85,918 shares ($3.85M)
- Jul 6, 2026: Fitzpatrick Jennifer sold 10,250 shares ($447K)
5%+ owners
- RA Capital Management, L.P.: 14.3% (Schedule 13D/A, filed Sep 21, 2026)
- VIKING GLOBAL INVESTORS LP: 7.1% (Schedule 13G/A, filed May 15, 2026)
- ORBIMED ADVISORS LLC: 6.6% (Schedule 13D/A, filed Apr 20, 2026)