What happened: Moderna (MRNA) stock rose 4% on Monday, extending its 12% rally on Friday.
What’s behind the move: The biotech is researching vaccines to protect against hantaviruses, a group of viruses that spread to humans through exposure to rodents.
Biotech and vaccine stocks could also be volatile on Monday on reports that President Trump plans to let go of Food and Drug Administration commissioner Marty Makary. The move could open the way for easing regulation.
What else you need to know: A cluster of hantavirus cases was linked to the MV Hondius Dutch cruise ship in May 2026. Several people became seriously ill, and at least three deaths were reported.