The National Football League has expressed concern over certain types of bets offered by prediction market apps. The league has written to these apps to reiterate its concerns about specific trades. Further details about the NFL's concerns and the types of trades in question are available from the source.

The NFL has described these bets as "objectionable" and is calling on the apps to ban them. The full context of the NFL's letter to prediction market apps can be found through additional reporting from the source.