Sportsbooks Are Building the Prediction Markets They Once Fought

When I last wrote about prediction markets, they looked to be heading toward a single legal showdown. 

States were suing to shut down sports contracts. Courts were splitting over whether those contracts were federally regulated swaps or ordinary wagers.

All that pressure remains, and tomorrow brings oral arguments in two Sixth Circuit appeals, another step toward what I believe is a preordained Supreme Court fight.

What’s changed is the incumbents. The sportsbooks once threatened by prediction markets have spent the past year building prediction-market businesses of their own, emboldened by federal support and Kalshi’s growth.

Regulators now face national brands using federal exchanges to offer sports contracts in states where their sportsbooks cannot operate, and openly saying so. That gives the state-led side its strongest argument yet that this is merely jurisdictional arbitrage.

Sportsbooks Bought Their Way In

Last fall, DraftKings bought CFTC-designated exchange Railbird. By year-end, it had launched DraftKings Predictions through CME while preparing to add Railbird’s markets. DraftKings said at launch that sports contracts would be available in states like California, Florida, Georgia, and Texas.

FanDuel launched FanDuel Predicts around the same time through CME. Earlier this summer, it added contracts from Crypto.com’s federally regulated exchange.

Fanatics also launched at the end of last year through Crypto.com. On Monday, it agreed to acquire Water Street Labs and CX Clearinghouse from BGC, giving it its own federally registered exchange and clearinghouse. Fanatics Markets already operates in states including California, Texas, and Florida.

FanDuel has been the most direct about what this is. It explicitly designed the product to offer sports contracts where online sports betting is not legal, and said it would withdraw them as those states legalize sportsbooks. The federal exchange is a placeholder until the state license arrives.

Where mobile sports betting exists, they keep operating sportsbooks under state law. Where betting is prohibited or limited, these federal exchanges let them offer nearly the same product to many of the same customers, forcing states to prove they can stop it. As a result, sportsbooks can now provide the same national reach Kalshi and Polymarket ServicesPolymarket is a popular, decentralized Prediction Market.View Profile” class=”stubHighlight”> Polymarket are building.

The Court Map Is Getting Messier

When I first wrote about Supreme Court inevitability in May, the federal side led in New Jersey and Tennessee, while states led in Nevada, Maryland, Massachusetts, and Ohio. Since then, Arizona, Minnesota, Michigan, New York, and Washington have cast new votes, putting the score at 4–7.

Yet the most important ruling still belongs to Kalshi.

The Third Circuit’s New Jersey decision in Kalshi’s favor came at the appellate level, carrying more weight than the rulings of the trial courts elsewhere (though not overruling them). At that level, the score is 1–0 for federal jurisdiction.

Prediction Markets Face a Full-Court Press on Bankless

Kalshi and Polymarket may have a wild road ahead as states wage war on sports markets and the public reckons with insider bets.

Tomorrow, the Sixth Circuit will hear Kalshi’s Tennessee and Ohio appeals together after two trial judges in the same circuit reached opposite conclusions. The court will not rule tomorrow, but the hearing provides the next appellate reading.

• If the court ultimately adopts Ohio’s reasoning and rejects the Third Circuit’s, it creates a circuit split and gives the Supreme Court its clearest reason yet to step in.
• If it adopts Kalshi’s theory, the appellate score moves to 2–0. That strengthens the federal position but doesn’t settle the issue nationwide. We still have decisions pending from the Fourth, Ninth (which seems likely to go against prediction markets), and Second Circuits, along with the Massachusetts Supreme Judicial Court, to reinforce that consensus or break it.

A Market Too Large to Leave Untested

Americans placed $166.94 billion in legal sports wagers in 2025, more than double the combined revenue of the U.S. movie, music, book, and museum industries.

A market that size will not sit still while the law gets sorted out. Sportsbooks will keep moving before the courts finish, and each state they enter this way hands the state-led side a cleaner argument: that these are sports betting products in all but name, offered through federal exchanges in states whose gambling laws kept their sportsbooks out.

While Kalshi and Polymarket started this fight, the sportsbooks have made it too big to end anywhere but the Supreme Court.