BlackRock
SION

BlackRock’s Sionna Therapeutics SION Stock Holding History

BlackRock’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 		$64.9M Buy
1,474,769
+178,902
+14% +$7.16M ﹤0.01% 2505
2026
Q1 		$52M Buy
1,295,867
+4,268
+0.3% +$163K ﹤0.01% 2475
2025
Q4 		$53.1M Buy
1,291,599
+446,994
+53% +$16.9M ﹤0.01% 2472
2025
Q3 		$24.8M Buy
844,605
+207,501
+33% +$4.51M ﹤0.01% 2952
2025
Q2 		$11.1M Buy
637,104
+438,708
+221% +$5.75M ﹤0.01% 3365
2025
Q1 		$2.08M Buy
+198,396
New +$3.24M ﹤0.01% 3988

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
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 40.89% 1-Year Est. Return

BlackRock's SION Position: Q2 2026 in Review

BlackRock increased its Sionna Therapeutics (SION) stake by 14% in Q2 2026, buying an estimated $7.16M and bringing the position to 1,474,769 shares worth $64.9M. The position accounts for ﹤0.01% of the portfolio, ranked #2505.

BlackRock 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.

  • BlackRock held 1,474,769 shares of Sionna Therapeutics worth $64.9M as of Q2 2026.
  • BlackRock bought 178,902 Sionna Therapeutics shares in Q2 2026, an estimated $7.16M.
  • Sionna Therapeutics made up ﹤0.01% of BlackRock's portfolio in Q2 2026, its #2505 holding.
  • BlackRock 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 BlackRock's 13F filing for Q2 2026, filed 7 Aug 2026.