LOS ANGELES — The NBA on Oct 26 announced commercial partnerships with Kalshi and Polymarket that the basketball league said will help safeguard against illegal activity on the wildly popular online prediction markets.

Kalshi and Polymarket will be officially designated the league’s “preferred prediction market exchanges”, and will be able to use NBA marketing materials for their promotions.

In return, the deal gives the NBA control over what specific trades the websites can offer, and obliges the companies to share information “relating to investigations and suspicious trading”.

It comes as prediction markets have exploded in popularity, benefiting from looser regulations that allow them currently to operate nationwide.

They are technically distinct from traditional sports betting, as there is no central sportsbook that sets odds. Instead, users place monetary wagers directly against one another via online exchanges.

Some states have questioned the difference. New York attorney general Letitia James this summer sued Kalshi, accusing it of running an illegal gambling operation.

Individual NBA stars including four-time NBA champion LeBron James and Giannis Antetokounmpo already have endorsement deals with Polymarket and Kalshi respectively.

Victor Wembanyama has been an outspoken critic, calling it “very sad to see some players promoting” sports gambling.

The NBA has been hit by multiple illegal gambling scandals in recent years.

In October 2025, Miami Heat guard Terry Rozier was among those arrested in a far-ranging FBI probe into illegal gambling.

Rozier, who has denied wrongdoing, was accused of providing inside information on injuries and game absences to bettors. He allegedly told co-conspirators he would exit early with a supposed injury from a March 2023 game when he was with the Charlotte Hornets.

This June, former Milwaukee Bucks player Malik Beasley was indicted on illegal gambling charges. In one example, Beasley is alleged to have informed a former teammate that he intended to underperform with respect to rebounding in a game.

Under the new deal, the NBA would be able to prevent markets that are especially susceptible to manipulation.

“Protecting the integrity of the game is our top priority,” Scott Kaufman-Ross, NBA head of media distribution and partnerships, said in a statement.

“As this category develops, we believe it is important to work constructively with regulators and operators to help ensure that appropriate safeguards are in place.”

The deal includes explicit prohibitions against league and team personnel trading on NBA-related markets.

The NBA also expanded its existing agreement with sportsbook partner DraftKings to include prediction markets.

Prediction markets have drawn broader controversy over allegations that insiders have used privileged information to make fortunes wagering on politics and even war. AFP