The major players in prediction markets steadfastly insist they are not gambling companies. That is a distinction that federal regulators have approved, allowing them to offer their sports events contracts even in states where sports betting is not legal.
At least two of America’s biggest pro sports leagues remain unconvinced of any meaningful difference.
Late in the 2025 season, Major League Baseball sent a memo directly prohibiting its players from engaging with baseball event contracts on Kalshi, Polymarket, and other prediction markets, Front Office Sports has learned.
The memo, obtained by FOS, was titled “Re: Baseball Related Prediction Markets” and was jointly sent to players from commissioner Rob Manfred’s office and the players’ union.
