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SION: 8 Funds Holding, Catalyst in 18d | BiotechEdge

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Home›Companies›Sionna Therapeutics, Inc. (SION)

Sionna Therapeutics, Inc.

SION

Held by 8 specialist biotech funds

High ConvergenceHigh short interest · No specialist buying

8 funds opened new positions. Next phase2 readout (SION-719): Jul 2026. Short interest: 18.0% of float.

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Data sourced from SEC EDGAR and ClinicalTrials.gov. Not investment advice.

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BiotechnologyCEO: Michael CloonanIPO: 2025Website ↗

Sionna Therapeutics, Inc. is a biopharmaceutical company. The Company provides treatment paradigm for cystic fibrosis patients by developing medicines that normalize the function of the cystic fibrosis transmembrane conductance regulator.

Score Holdings Short Interest Catalysts Insiders Research

Signal Score

6.5/10

8 funds opened new positions●●

No recent insider activity●●

Phase2 readout in 18 days●●

Held by 8 specialist funds●●

See how each signal contributes— fund overlap, insider activity, catalyst timing, short interest (free trial)

Conviction + Catalyst

8 specialist funds hold SION with a Phase 2 in 18 days for SION-719 (Cystic Fibrosis (CF))

Perceptive Advisors Rock Springs Capital RA Capital Management OrbiMed Advisors Eventide Asset Management Baker Bros. Advisors Deerfield Management Driehaus Capital

Fund Holdings

8 fund convergence

Perceptive AdvisorsHeld 5Q ↓

Rock Springs CapitalHeld 5Q

RA Capital ManagementHeld 5Q

OrbiMed AdvisorsHeld 5Q

Eventide Asset ManagementHeld 2Q

Baker Bros. AdvisorsHeld 5Q

Deerfield ManagementHeld 5Q ↑

Driehaus CapitalHeld 5Q ↓

Position history (shares)

Perceptive Advisors

5Q

Rock Springs Capital

5Q

RA Capital Management

5Q

OrbiMed Advisors

5Q

Eventide Asset Management

2Q

Baker Bros. Advisors

5Q

Deerfield Management

5Q

Driehaus Capital

5Q

AI Signal

Sionna Therapeutics (SION) — Eventide adds modestly ahead of key CF readout

Eventide added a small incremental position (+6,485 shares, ~1% of existing stake) in SION, maintaining a $25.9M core holding as the company approaches a Phase 2 readout for SION-719 in cystic fibrosis, expected by July 2026. The more notable signal here is fund convergence: 8 specialist biotech funds — including RA Capital, OrbiMed, Baker Bros., and Perceptive — hold this name, reflecting high-conviction institutional alignment around the CF catalyst.

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5 quarters

Position Trend

Feb 13, 2026

$26.3M

1 fund

Feb 17, 2026

$666.5M

7 funds

May 15, 2026

$626.5M

7 funds

May 29, 2026

$26.4M

1 fund

-84% total institutional value over 8 quarters

Short Interest

High short interestSI rising 2 periods (+7.7%)

Short Shares

5.00M

Change

+5.4%

Days to Cover

14.6

% of Float

18.0%

Settlement

Jun 15, 2026

Short interest over 10 periods

Catalysts

Phase 2Q3 2026SION-719Cystic Fibrosis (CF)NCT07108153

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Activist Filings

SC 13D/AOrbiMed Advisors6.6%Apr 20, 2026

SC 13D/ARA Capital Management22.6%Nov 7, 2025

SC 13DRA Capital Management23.7%Feb 18, 2025

SC 13DOrbiMed Advisors8.4%Feb 13, 2025

Position Details

Perceptive AdvisorsTRIMMEDMay 29, 2026

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Also Held by These Funds

ARGX1 fund ACAD1 fund RVMD1 fund VTVT1 fund REPL1 fund KYMR1 fund MDGL1 fund DBVTF1 fund

Research Links

Yahoo Finance →SEC EDGAR →ClinicalTrials.gov →

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