Polymarket traders are betting on a 79% chance of at least one confirmed hantavirus case in the US by May 15, driven by a recent outbreak on the MV Hondius cruise ship. The prediction market has seen $348,000 in trading volume, with $217,000 entering during a recent surge. The outbreak involved the Andes strain, known for person-to-person transmission, resulting in three deaths. Despite the heightened activity, hantavirus is endemic in the US, with 30 to 50 cases typically reported annually. The probability of a hantavirus pandemic in 2026 remains low at 9%, with no historical precedent for such an event. Investors are advised to consider resolution criteria carefully, as reporting delays or classification issues could affect outcomes.