Wisconsin Sues Prediction Markets, Escalating State Fight Over Sports Event Contracts

Wisconsin’s Department of Justice has sued Kalshi, Polymarket, Coinbase, Robinhood, Crypto.com and affiliated entities, alleging that sports-related event contracts amount to illegal sports betting under state law. The complaints, filed in Dane County circuit court, seek to stop the platforms from offering what Attorney General Josh Kaul described as unlawful commercial gambling in Wisconsin.

State gambling law meets federal market structure

The core legal question is classification. Wisconsin argues that fixed-payout contracts tied to sports outcomes are functionally indistinguishable from wagers, while platforms and distribution partners have generally framed prediction markets as federally regulated event contracts under CFTC oversight. The Wisconsin complaints cite the state’s longstanding prohibition on sports betting outside limited tribal gaming arrangements.

That puts Wisconsin into a widening federal-state conflict. The CFTC has already sued several states to defend what it says is its exclusive jurisdiction over prediction markets, while courts have split on whether state gambling regulators can restrict CFTC-linked sports contracts.

Platforms now face fragmentation risk

State-by-state enforcement could force geofencing, segmented liquidity and heavier KYC controls, especially for broker partners distributing contracts through APIs or app interfaces. That would make markets thinner, raise slippage and increase compliance latency around order routing.

The lawsuits also raise the stakes for legislative intervention. Bills such as the PREDICT Act show Congress is already weighing how prediction markets should be policed, particularly where public officials, government information or politically sensitive events are involved.

The near-term takeaway is clear: prediction markets are no longer facing only product-risk scrutiny; they are facing infrastructure-level legal risk. Until courts resolve preemption, operators should expect a patchwork operating environment where state access, liquidity and product availability vary sharply by jurisdiction.