SL
SION

Siren LLC’s Sionna Therapeutics SION Stock Holding History

Siren LLC’s Portfolio SION Stock Details SION Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$26.9M Buy
610,515
+310,515
+104% +$12.4M 0.54% 46
2026
Q1 		$12M Hold
300,000
– – 0.33% 55
2025
Q4 		$12.3M Sell
300,000
-25,000
-8% -$948K 0.37% 47
2025
Q3 		$9.56M Hold
325,000
– – 0.37% 48
2025
Q2 		$5.64M Hold
325,000
– – 0.29% 58
2025
Q1 		$3.4M Buy
+325,000
New +$5.31M 0.19% 73

Other funds holding SION

RCM
RA Capital Management Boston, Massachusetts $11.5B AUM 168.77% 1-Year Est. Return
TGA
TPG GP A Fort Worth, Texas $5B AUM 58.56% 1-Year Est. Return
Viking Global Investors
Viking Global Investors Stamford, Connecticut $35.1B AUM 21.36% 1-Year Est. Return
AVLSA
Atlas Venture Life Science Advisors Cambridge, Massachusetts $881M AUM 160.77% 1-Year Est. Return
O
OrbiMed New York $5.4B AUM 163.13% 1-Year Est. Return
ES
Enavate Sciences Menlo Park, California $345M AUM 134.64% 1-Year Est. Return
Adage Capital Partners
Adage Capital Partners Boston, Massachusetts $71.3B AUM 56.8% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
JP Morgan Chase
JP Morgan Chase New York $1.81T AUM 41.13% 1-Year Est. Return
Jennison Associates
Jennison Associates New York $167B AUM 44.17% 1-Year Est. Return

Siren LLC's SION Position: Q2 2026 in Review

Siren LLC increased its Sionna Therapeutics (SION) stake by 104% in Q2 2026, buying an estimated $12.4M and bringing the position to 610,515 shares worth $26.9M. The position accounts for 0.54% of the portfolio, ranked #46.

Siren LLC first reported a position in SION in Q1 2025 and has held it in 6 quarters since. 146 funds tracked by Wall St. Rank hold SION as of Q2 2026.

  • Siren LLC held 610,515 shares of Sionna Therapeutics worth $26.9M as of Q2 2026.
  • Siren LLC bought 310,515 Sionna Therapeutics shares in Q2 2026, an estimated $12.4M.
  • Sionna Therapeutics made up 0.54% of Siren LLC's portfolio in Q2 2026, its #46 holding.
  • Siren LLC first reported a position in Sionna Therapeutics in Q1 2025 and has held it in 6 quarters since.
  • 146 funds tracked by Wall St. Rank held Sionna Therapeutics as of Q2 2026.

Based on Siren LLC's 13F filing for Q2 2026, filed 13 Aug 2026.