Why Sionna Therapeutics Stock Is Crashing 91% to a Record Low Barron's SION Stock On Track For Worst Day Ever After 90% Drop — What’s Driving The Selloff? Yahoo Finance Sionna’s cystic fibrosis flop sends stock down 90%, but a ‘significant positive’ for Vertex fiercebiotech.com Sionna Therapeutics stock plunges nearly 100% after cystic fibrosis drug fails key trial The Business Journals Why Vertex Pharma Popped, As A Key Rival Plummeted 92% Investor's Business Daily