On September 12, several healthcare and biotech stocks experienced a surge in after-hours trading, marked by sharp price movements across the sector. From thrombectomy devices to AI-powered diagnostics and T-cell therapies, companies including Penumbra, Check-Cap, Adaptimmune Therapeutics, and NewAmsterdam Pharma posted notable gains after hours. While some moves were tied to strategic announcements or clinical milestones, others came without direct news, highlighting a volatile and active session for the ...