TL;DR
- Wisconsin sued Kalshi, Robinhood, Coinbase, Polymarket and Crypto.com, saying sports event contracts offered to residents are illegal gambling under state law.
- The complaints seek injunctions, target Kalshi’s sports-heavy business, and arrive as state and federal authorities keep clashing over whether these contracts are wagers or derivatives.
- The case could shape how fast-growing prediction markets are classified as pressure spreads well beyond Wisconsin across the United States now.
Wisconsin has opened a new front in the fight over prediction markets, suing Kalshi, Robinhood, Coinbase, Polymarket and Crypto.com over sports event contracts that the state says amount to illegal gambling. What makes the case feel bigger than an enforcement action is that it targets not just niche prediction platforms, but gateways through which users reach these markets. The complaints were filed April 23 in Dane County, with Attorney General Josh Kaul seeking injunctions and a judicial declaration that the businesses are operating unlawfully under Wisconsin law and as a public nuisance.
The state’s argument is blunt. Wisconsin is saying that calling these products “event contracts” does not change what they are when money is paid out based on sports outcomes and fees are collected from local users. The complaints allege the platforms list contracts that pay money according to event results, charge per trade, and generate revenue from Wisconsin residents in violation of state law. Kalshi receives special attention, with filings asserting that sports contracts make up almost 90% of its business and annualized revenue from those products exceeds $1 billion.
The legal clash is spreading faster than the rules can settle
The Wisconsin case lands in a national environment pulling in opposite directions. State gambling enforcers keep treating sports event contracts as unlicensed wagering, while federal authorities and some courts are more willing to view certain contracts through the lens of derivatives law. Earlier in April, a Nevada judge extended an order blocking Kalshi from offering sports markets there, and Arizona authorities also pursued enforcement tied to the company’s contracts. At the same time, federal regulators and the Justice Department have supported arguments that some event contracts fit within the federal derivatives framework.
That split is why this lawsuit matters. The deeper question is no longer whether these markets are growing, but which legal system gets to define them before the category becomes too large to contain easily. The pressure is not limited to Wisconsin. In January, Tennessee regulators sent cease-and-desist letters to Kalshi, Polymarket and Crypto.com, while Robinhood and Coinbase expanded access through non-exclusive deals routing customer orders to Kalshi. With billions moving through these products, Wisconsin’s case could help decide whether prediction markets are treated as financial innovation or as sports betting under another name.
