MLB and Polymarket: A New Era for Prediction Markets in Baseball

Major League Baseball (MLB) is deepening its involvement in the burgeoning world of prediction markets through a new partnership with Polymarket. The agreement, announced on March 19, 2026, aims to establish a comprehensive integrity framework for these markets even as offering fans new ways to engage with the game. However, the scope of the partnership is currently focused on Polymarket’s U.S.-based exchange, which represents a small fraction of the company’s overall trading volume.

Partnership Details and Integrity Focus

MLB has named Polymarket its Official Prediction Market Exchange . As part of the deal, Polymarket and its brokers will gain exclusive access to MLB logos and branding for use in their prediction market products. They will also receive access to official league data from Sportradar, MLB’s exclusive global distributor of prediction market data .

A key component of the partnership is the establishment of an integrity framework. MLB and Polymarket will collaborate to restrict markets that could pose a risk to the integrity of the game, such as those focused on individual pitches, manager decisions, or umpire performance . Polymarket will also integrate integrity controls into its U.S. Rulebook to ensure consistent standards for all brokers.

CFTC Collaboration

Alongside the Polymarket partnership, MLB Commissioner Robert D. Manfred, Jr. Signed a memorandum of understanding (MOU) with Michael S. Selig, Chairman of the Commodity Futures Trading Commission (CFTC) . This MOU formalizes a commitment to share information regarding the integrity of professional baseball and related prediction markets. The agreement follows MLB’s previous call for strong integrity protections in the prediction market space.

Limited Scope of the Agreement

Despite the fanfare, the current agreement primarily focuses on Polymarket’s relatively small U.S. Prediction market exchange. As of March 2026, the notional betting volume on Polymarket U.S. Is approximately $700 million, significantly less than the $20 billion volume on its international exchange . Kalshi, a competitor, recorded $3 billion in notional volume in a single week .

The international exchange, which is not subject to the same restrictions as the U.S. Exchange, has drawn scrutiny for allowing bets on events like military strikes and political outcomes . It also does not require users to provide personal identification, raising concerns about potential illicit activity.

MLB’s Broader Strategy

While Polymarket has exclusive rights as MLB’s official partner, the league will maintain relationships with other prediction market exchanges that offer baseball contracts . Polymarket also has exclusive licensing deals with Major League Soccer and a non-exclusive agreement with the National Hockey League .

This partnership represents MLB’s continued embrace of sports betting and its efforts to navigate the evolving landscape of prediction markets. The league aims to balance innovation and fan engagement with the need to protect the integrity of the game.