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RA CAPITAL MANAGEMENT, L.P.

Position in SION — Sionna Therapeutics, Inc.

CIK 1346824 BOSTON, MA

Position in SION

as of Mar 31, 2026 · filed May 15, 2026
Position Value
$397,093,254
-$10,400,297 QoQ
Shares Held
9,905,045
0.0% QoQ
Ownership
21.9%
of shares outstanding
% of Portfolio
4.21%
of 13F equity value
Holder Rank
#1
of 121 holders
Holding Since
Mar 2025
5 quarters on record
Voting authority Sole 100.ToString("F0")% Shared 0.ToString("F0")% None 0.ToString("F0")%

Common Shares in SION Over Time

Shares Held

Position Value (USD)

Position in Biotechnology

Healthcare · as of Mar 31, 2026

RA CAPITAL MANAGEMENT, L.P. holds $9,134,713,488 across 74 Biotechnology names. SION ranks #5 (4.3% of the industry book) .

# Ticker Company Shares Value (USD) Open
5 SION
Sionna Therapeutics, Inc.
This page
9,905,045 $397,093,254

All Filings in SION

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7 filing rows on record
Report Date Value (USD) Shares
2026-03-31 $397,093,254 9,905,045
2025-12-31 $407,493,551 9,905,045
2025-11-05 $353,315,656 10,071,712
2025-09-30 $307,196,920 10,445,322
2025-06-30 $181,226,336 10,445,322
2025-03-31 $109,258,068 10,445,322
2025-02-10 $232,303,961 10,445,322