American Century Companies
SION

American Century Companies’s Sionna Therapeutics SION Stock Holding History

American Century Companies’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 		– Sell
-6,180
Closed -$254K – 2940
2025
Q4 		$254K Buy
+6,180
New +$234K ﹤0.01% 2660

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

American Century Companies's SION Position: Q1 2026 in Review

American Century Companies sold out of Sionna Therapeutics (SION) in Q1 2026, closing a stake of 6,180 shares — an estimated $254K sold.

American Century Companies first reported a position in SION in Q4 2025 and held it in 1 quarter. The position peaked at $254K in Q4 2025. 122 funds tracked by Wall St. Rank hold SION as of Q1 2026.

  • American Century Companies reported no remaining Sionna Therapeutics position as of Q1 2026 after selling out during the quarter.
  • American Century Companies sold 6,180 Sionna Therapeutics shares in Q1 2026, an estimated $254K.
  • American Century Companies first reported a position in Sionna Therapeutics in Q4 2025 and held it in 1 quarter.
  • American Century Companies's Sionna Therapeutics position peaked at $254K in Q4 2025.
  • 122 funds tracked by Wall St. Rank held Sionna Therapeutics as of Q1 2026.

Based on American Century Companies's 13F filing for Q1 2026, filed 15 May 2026.