For the past few years, the sports-betting throne has been shared by two major players: DraftKings and FanDuel. These betting platforms have millions of users and generate billions of dollars in revenue. Turn on any major league sports game and there’s a good chance you’ll see ads or promotions for one of these companies.

Yet investors are unsure about their future. Shares of DraftKings

DKNG and Flutter Entertainment FLUT, the parent company of FanDuel, have fallen dramatically over the past few weeks as investors weigh a potential threat coming from outside the sports-betting industry: prediction markets like Kalshi and Polymarket.