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
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 $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
Citadel Advisors
Citadel Advisors Miami, Florida $618B AUM 30.34% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

BlackRock's SION Position: Q1 2026 in Review

BlackRock increased its Sionna Therapeutics (SION) stake by 0.33% in Q1 2026, buying an estimated $163K and bringing the position to 1,295,867 shares worth $52M. The position accounts for ﹤0.01% of the portfolio, ranked #2475.

BlackRock first reported a position in SION in Q1 2025 and has held it in 5 quarters since. The position peaked at $53.1M in Q4 2025. 122 funds tracked by Wall St. Rank hold SION as of Q1 2026.

  • BlackRock held 1,295,867 shares of Sionna Therapeutics worth $52M as of Q1 2026.
  • BlackRock bought 4,268 Sionna Therapeutics shares in Q1 2026, an estimated $163K.
  • Sionna Therapeutics made up ﹤0.01% of BlackRock's portfolio in Q1 2026, its #2475 holding.
  • BlackRock first reported a position in Sionna Therapeutics in Q1 2025 and has held it in 5 quarters since.
  • BlackRock's Sionna Therapeutics position peaked at $53.1M in Q4 2025.
  • 122 funds tracked by Wall St. Rank held Sionna Therapeutics as of Q1 2026.

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