O
SION

OrbiMed’s Sionna Therapeutics SION Stock Holding History

OrbiMed’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 		$142M Sell
3,530,702
-30,953
-0.9% -$1.18M 2.81% 8
2025
Q4 		$147M Sell
3,561,655
-143,304
-4% -$5.43M 2.99% 8
2025
Q3 		$109M Hold
3,704,959
– – 2.56% 11
2025
Q2 		$64.3M Hold
3,704,959
– – 1.61% 19
2025
Q1 		$38.8M Buy
+3,704,959
New +$60.5M 0.92% 31

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
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
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

OrbiMed's SION Position: Q1 2026 in Review

OrbiMed reduced its Sionna Therapeutics (SION) stake by 0.87% in Q1 2026, selling an estimated $1.18M and leaving 3,530,702 shares worth $142M. The position accounts for 2.81% of the portfolio, ranked #8.

OrbiMed first reported a position in SION in Q1 2025 and has held it in 5 quarters since. The position peaked at $147M in Q4 2025. 122 funds tracked by Wall St. Rank hold SION as of Q1 2026.

  • OrbiMed held 3,530,702 shares of Sionna Therapeutics worth $142M as of Q1 2026.
  • OrbiMed sold 30,953 Sionna Therapeutics shares in Q1 2026, an estimated $1.18M.
  • Sionna Therapeutics made up 2.81% of OrbiMed's portfolio in Q1 2026, its #8 holding.
  • OrbiMed first reported a position in Sionna Therapeutics in Q1 2025 and has held it in 5 quarters since.
  • OrbiMed's Sionna Therapeutics position peaked at $147M in Q4 2025.
  • 122 funds tracked by Wall St. Rank held Sionna Therapeutics as of Q1 2026.

Based on OrbiMed's 13F filing for Q1 2026, filed 15 May 2026.