Kalshi and Polymarket have been asked by the NFL to stop offering bets on specific game elements that can be easily manipulated, such as what announcers say during broadcasts and which celebrities attend games. The league sent letters to these prediction market operators outlining four prohibited categories, including events knowable in advance like draft picks and coach firings. This move aims to protect players from unfair gambling allegations and preserve game integrity, though the NFL hasn't yet partnered with these platforms.

The Commodity Futures Trading Commission (CFTC) is coordinating with leagues to identify vulnerable markets, with MLB and NHL already forming partnerships. Michael Selig, the CFTC chair, emphasized the agency's deference to league expertise on manipulation risks.