The unions supporting professional athletes from the NBA, NFL and MLB have called on the Commodity Futures Trading Commission (CFTC) to ban prediction market platforms from allowing bets on a player’s underperformance or injury. In their letter, the unions argue that such 'unders' bets expose athletes and their families to abusive behavior.

The move comes in response to the CFTC's request for comments on regulating prediction markets. The unions are not only seeking a ban on these controversial wagers but also want to stop betting on negative outcomes during broadcasts, like mentions of 'concussion.'

History has shown how serious the issue can be; Jontay Porter, former Toronto Raptors center, pleaded guilty to conspiracy in 2024 for limiting his own game play for betting purposes. The NBA and US Department of Justice have also charged several players with using private information to enrich themselves.

The unions are urging the CFTC to prohibit the unauthorized use of player-related data such as injury details, performance metrics or health records. They add that the NBA wants to restrict prediction market betting to those aged 21 and over, in line with Kalshi and Polymarket’s currently lower age threshold.

As prediction markets gain popularity, so does their legal battle, with the CFTC challenging state attempts at regulation. States like Arizona, Connecticut, Illinois, New York, and Wisconsin find themselves in court for attempting to impose rules on platforms they see as out of their jurisdiction.