Michigan Attorney General Dana Nessel has filed a civil enforcement action against Kalshi in the 30th Judicial Circuit Court of Ingham County, leading to preemptive action from Polymarket which cited concerns of an “immediate and concrete” threat following Nessel’s lawsuit.
The complaint against Kalshi states: “Kalshi offers an online sports betting operation to residents in the State of Michigan without the licensing approval of the Michigan Gaming Control Board (MGCB).
“Specifically, Kalshi operates a so-called prediction market through which residents of the State of Michigan can engage in unlicensed gambling under the guise of trading event contracts. In each case, the bettors’ return is determined entirely by an outcome outside their control.”
Nessel’s lawsuit cites specific examples of Kalshi markets which violate Michigan gaming laws, including event contract trading for hockey, golf, college basketball and the NBA.
Michigan now represents the 10th state across the US to become engaged in litigation with the prediction markets operator, but just the third to file a lawsuit as a plaintiff in state court.
Similar to arguments made by regulators in Nevada, the lawsuit states Kalshi has continued to enhance its sports-related contracts offering, such as the ability to bet on individual player touchdowns, margins of victory, total game scores and outcomes which bundle multiple events.
In April 2025, MGCB Executive Director Henry Williams seemingly addressed the growing concern surrounding prediction markets, having said, “Unlicensed entities not only pose a risk to consumers but also undercut the integrity and revenue-generating potential of the state’s regulated sports betting industry.
“We are actively investigating these practices and will pursue appropriate measures to protect Michigan bettors.”
Following the lawsuit filed by Nessel, Polymarket preemptively filed its own enforcement action against the Michigan Attorney General in federal court, seeking to “prevent imminent and irreparable harm arising from Michigan’s enforcement of state gambling laws against federally regulated derivatives exchanges.”
Again mirroring action from Nevada regulators, it is expected Nessel will attempt to move the case against Polymarket to state court, such as what the Silver State has already managed to do for litigation with Kalshi and Polymarket.
Betr formed a multi-year partnership with Polymarket on March 4 to begin offering a prediction markets product to users, including the ability to trade events contracts across sports, politics, culture and more
