Polymarket Strikes Historic MLB Deal as Arizona Files Criminal Charges Against Rival Kalshi

Polymarket becomes the exclusive MLB prediction market partner while Kalshi deals with a criminal indictment in Arizona. Get the full industry roundup here.

By: AXL Media

Published: Mar 21, 2026, 5:30 AM EDT

Source: The information in this article was sourced from iGB

Polymarket Secures Exclusive Partnership With Major League Baseball

Major League Baseball has officially entered the prediction market sector by designating Polymarket as its exclusive exchange partner just ahead of the 2026 Opening Day. This commercial alliance places MLB alongside other major North American organizations, including the NHL and UFC, that have embraced the burgeoning industry. Commissioner Rob Manfred noted that while the league is expanding its commercial footprint, the primary focus remains on safeguarding the sport's competitive honesty. The deal followed a briefing with team owners regarding the strategic advantages of integrating with decentralized exchange platforms.

Federal Regulators and MLB Establish Integrity Framework

Concurrent with the Polymarket announcement, the U.S. Commodity Futures Trading Commission and MLB signed a formal Memorandum of Understanding to coordinate oversight. This agreement creates a structured channel for exchanging information to combat fraud and market manipulation within baseball-related derivatives. CFTC Chairman Michael Selig characterized the partnership as a vital step in adding modern tools to the agency’s regulatory arsenal. The move reinforces the CFTC’s assertion of exclusive jurisdiction over event contracts, even as the industry faces intensifying pushback from individual state authorities.

Arizona Attorney General Levels Criminal Charges Against Kalshi

While Polymarket celebrates its expansion, its competitor Kalshi is grappling with a landmark legal challenge in the Southwest. Arizona Attorney General Kris Mayes unsealed a 20-count criminal indictment against KalshiEx LLC and Kalshi Trading LLC, alleging the operation of an unlicensed gambling business. The charges specifically target Kalshi’s offerings on political outcomes, such as the 2026 Arizona gubernatorial race and the 2028 presidential election. Mayes asserted that the company cannot self-define its regulatory status to bypass state laws that strictly prohibit wagering on elections.