NBA star LeBron James announced a partnership with the prediction market platform Polymarket via a video on X. The collaboration follows the expiration of James's endorsement deal with sportsbook DraftKings earlier this summer. The platform plans a full reveal of the partnership on Tuesday.
The prediction market sector has seen significant growth, with monthly volume reaching $20 billion by January, compared to $1.2 billion in early 2025. Betting volume on the market regarding James's next team exceeded $245 million this summer. NBA rules permit players to promote prediction markets, provided the contracts are not tied to NBA games.
Competition in the space is intensifying, with Giannis Antetokounmpo becoming a shareholder in rival platform Kalshi earlier this year. Major sports leagues have also engaged with these operators; Polymarket is the official provider for Major League Baseball, and the NHL signed deals with both platforms in October 2025.
Regulatory challenges persist as Baltimore sued both Polymarket and Kalshi in August, labeling them unlicensed sportsbooks. New York also filed a lawsuit against Kalshi in July for over $36 billion. Despite these legal pressures, Polymarket sought $400 million in funding at a $15 billion valuation in April, up from $9 billion in October 2024.
The Intercontinental Exchange, owner of the New York Stock Exchange, has committed $2 billion to Polymarket. The platform continues to expand its offerings beyond politics and sports, recently adding markets for Pokemon cards in August. The financial terms of the deal with LeBron James remain undisclosed.
