Not enough upsets in the National Football League (NFL) season will hurt results for FanDuel parent Flutter Entertainment (FLUT).

The online gambling firm reported it was slashing its full-year U.S. guidance because of the success of bettors in game wagering.

Flutter explained that in November and December, "continued strong U.S. player momentum has been offset by a period of very unfavorable U.S. sports results," primarily because of NFL Parlay and Same Game Parlay outcomes.

NFL Favorites Winning at High Clip

It noted that the current NFL season to date "has been the most customer friendly since the launch of online sports betting with the highest rate of favorites winning in nearly 20 years."

The company said in the U.S., those customer-friendly outcomes created lower revenue of about $390 million and adjusted EBITDA of some $260 million in the period spanning from Nov. 12 to Dec. 31.

Flutter now anticipates 2024 U.S. revenue of $5.78 billion, down from its previous outlook of $6.05 billion to $6.25 billion, and adjusted EBITDA of $505 million versus the earlier expectation of $670 million to $750 million.

The news didn't hurt shares of Flutter Entertainment, which were slightly higher Wednesday morning, possibly on a note from Oppenheimer, which indicated that despite the news, it remains "confident in FLUT's risk-management following two straight unfavorable NFL regular seasons."