Polymarket faces scrutiny as prediction markets ink massive deals with sports leagues

Prediction markets and professional sports leagues are getting very cozy, very fast. Polymarket locked down a $300 million, four-year deal as Major League Baseball’s exclusive prediction-market partner in the US and Canada back in March 2026, and that was just one domino in a chain that now stretches across multiple leagues and platforms. The problem: roughly 20 states disagree with the premise that these platforms are anything other than gambling operations wearing a fancier hat. The collision between rapid commercial expansion and state-level legal pushback is shaping up to be one of the more consequential regulatory fights in both sports and finance. The partnership blitz The timeline of deals tells a clear story of acceleration. The NHL partnered with both Polymarket and Kalshi in October 2025, making it one of the first major North American leagues to formally embrace prediction markets. MLS followed in January 2026 with an exclusive deal with Polymarket. Then MLB went big in March 2026 with that $300 million exclusive arrangement. By August 2026, Kalshi had carved out its own niche, securing branding deals with five individual MLB teams. Combined with Polymarket’s league-leve...