NFL presses Kalshi and Polymarket to drop objectionable bets

The NFL has asked prediction-market operators including Kalshi and Polymarket to stop offering a set of sports-related contracts it says could threaten game integrity, according to a letter obtained by ABC News. The league said those bets were still being listed on exchanges, and ABC News reported that this was the second time it had raised concerns about prediction markets.

In the letter, sent Thursday by chief compliance officer Sabrina Perel, the NFL said it was "deeply concerning" that contracts in the objectionable categories it identified months ago "have been and continue to be listed." The league warned that continuing to list those contracts threatens "the underlying integrity of our games" and creates significant risks for players, coaches, officials and people trading on the exchanges.

The objectionable categories included fan safety, player injuries, player misconduct, broadcast mentions, celebrity attendance and officiating. The league also singled out wagers on whether a player is "in and out" during a particular week, along with bets such as how many flags will be thrown. It said broadcast-mention and celebrity-attendance contracts can be easily manipulated by one person.

Yahoo Sports reported that the NFL framed its concerns in four broad groups: markets easily controlled by one person, markets knowable in advance, inherently objectionable safety-related markets and officiating-related contracts. The report said the league first wrote to operators at the end of March.

The wider market for sports event contracts has grown quickly. A Congressional Research Service report said sports are the most popular event-contract type by volume. It said that as of February, roughly 87% of Kalshi's $39.7 billion traded in the past year was on sports, while 38% of Polymarket's $36.2 billion traded in the last year was on sports.

The CRS said prediction markets are exchange platforms that offer binary event contracts, and that sports contracts have been offered by CFTC-regulated exchanges since early 2025 after a more permissive stance under new leadership in January 2025. It said Kalshi runs a CFTC-regulated exchange, while Polymarket's main exchange is offshore and says it blocks U.S. users.

ABC News also said prediction markets are now part of a nationwide legal battle, with several states seeking to ban or regulate them over allegations of unlicensed gambling. Separate from the NFL letter, Sportico reported that Kalshi removed injury-duration markets from its app after a CFTC request, after the agency said such bets could create perverse financial incentives and raise confidentiality concerns.