RSCM
SION

Rock Springs Capital Management’s Sionna Therapeutics SION Stock Holding History

Rock Springs Capital Management’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
Q1 		$3.99M Hold
99,429
– – 0.23% 69
2025
Q4 		$4.09M Hold
99,429
– – 0.21% 79
2025
Q3 		$2.92M Hold
99,429
– – 0.17% 73
2025
Q2 		$1.73M Hold
99,429
– – 0.11% 78
2025
Q1 		$1.04M Buy
+99,429
New +$1.62M 0.06% 87

Other funds holding SION

RCM
RA Capital Management Boston, Massachusetts $9.44B AUM 157.3% 1-Year Est. Return
TGA
TPG GP A Fort Worth, Texas $3.68B AUM 14.99% 1-Year Est. Return
O
OrbiMed New York $5.05B AUM 125.28% 1-Year Est. Return
Viking Global Investors
Viking Global Investors Stamford, Connecticut $35.7B AUM 21.3% 1-Year Est. Return
AVLSA
Atlas Venture Life Science Advisors Cambridge, Massachusetts $790M AUM 223.66% 1-Year Est. Return
ES
Enavate Sciences Menlo Park, California $352M AUM 220.14% 1-Year Est. Return
Jennison Associates
Jennison Associates New York $145B AUM 34.61% 1-Year Est. Return
JP Morgan Chase
JP Morgan Chase New York $1.56T AUM 27.86% 1-Year Est. Return
BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
Citadel Advisors
Citadel Advisors Miami, Florida $618B AUM 30.34% 1-Year Est. Return

Rock Springs Capital Management's SION Position: Q1 2026 in Review

Rock Springs Capital Management held its Sionna Therapeutics (SION) position steady in Q1 2026 at 99,429 shares worth $3.99M. The position accounts for 0.23% of the portfolio, ranked #69.

Rock Springs Capital Management first reported a position in SION in Q1 2025 and has held it in 5 quarters since. The position peaked at $4.09M in Q4 2025. 122 funds tracked by Wall St. Rank hold SION as of Q1 2026.

  • Rock Springs Capital Management held 99,429 shares of Sionna Therapeutics worth $3.99M as of Q1 2026.
  • Rock Springs Capital Management left its Sionna Therapeutics share count unchanged in Q1 2026.
  • Sionna Therapeutics made up 0.23% of Rock Springs Capital Management's portfolio in Q1 2026, its #69 holding.
  • Rock Springs Capital Management first reported a position in Sionna Therapeutics in Q1 2025 and has held it in 5 quarters since.
  • Rock Springs Capital Management's Sionna Therapeutics position peaked at $4.09M in Q4 2025.
  • 122 funds tracked by Wall St. Rank held Sionna Therapeutics as of Q1 2026.

Based on Rock Springs Capital Management's 13F filing for Q1 2026, filed 15 May 2026.