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ISSUER PROFILE · CIK 0002036042 · CUSIP 829401108

Sionna Therapeutics, Inc.SION

1 13D/G filings 1 distinct filers 0 insider transactions (365d)

Post-Filing Returns · across 1 activist filings on this issuer

Median 30d
avg —
Median 60d
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Median 90d
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Median 180d
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Returns measured from each activist filing's date_of_event, split + dividend adjusted via Yahoo Finance.

Cross-Reference Snapshot

Activist filings
1
1 SCHEDULE
Distinct filers
1
single filer
Insiders (365d)
0
0 buys · 0 sales
Latest short DTC
11.29
as of 2026-03-31

13D/G Filings Timeline · 1 total

FiledFormFilerStakeSharesIntent
2025-11-07 SCHEDULE RA CAPITAL MANAGEMENT, L.P. 22.60% 10,071,712 view →

FINRA Short Interest History

SettlementShort InterestDays to Cover% Δ vs prior
2026-03-31 3,756,705 11.29 +6.0%
2026-03-13 3,544,166 12.34 +5.8%
2026-02-27 3,350,255 23.36 +9.3%
2026-02-13 3,064,857 7.53 -2.5%
2026-01-30 3,143,560 13.55 +2.9%
2026-01-15 3,053,667 9.78 -6.3%
2025-12-31 3,258,091 8.47 +13.3%
2025-12-15 2,876,610 9.94 +0.5%

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