AH
SION

Andreas Halvorsen’s Sionna Therapeutics SION Stock Holding History

Andreas Halvorsen’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 		$141M Hold
3,195,181
– – 0.4% 61
2026
Q1 		$128M Hold
3,195,181
– – 0.36% 58
2025
Q4 		$131M Hold
3,195,181
– – 0.35% 64
2025
Q3 		$94M Hold
3,195,181
– – 0.24% 65
2025
Q2 		$55.4M Buy
3,195,181
+242,427
+8% +$3.18M 0.16% 75
2025
Q1 		$30.9M Buy
+2,952,754
New +$48.2M 0.1% 80

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
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
Citadel Advisors
Citadel Advisors Miami, Florida $875B AUM 40.91% 1-Year Est. Return

Andreas Halvorsen's SION Position: Q2 2026 in Review

Andreas Halvorsen held its Sionna Therapeutics (SION) position steady in Q2 2026 at 3,195,181 shares worth $141M. The position accounts for 0.4% of the portfolio, ranked #61.

Andreas Halvorsen 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.

  • Andreas Halvorsen held 3,195,181 shares of Sionna Therapeutics worth $141M as of Q2 2026.
  • Andreas Halvorsen left its Sionna Therapeutics share count unchanged in Q2 2026.
  • Sionna Therapeutics made up 0.4% of Andreas Halvorsen's portfolio in Q2 2026, its #61 holding.
  • Andreas Halvorsen 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 Viking Global Investors's 13F filing for Q2 2026, filed 14 Aug 2026.