TLDR Polymarket US must close existing Michigan sports contracts by November 25 under a federal court-approved deal. Kalshi, Coinbase and Robinhood have also stopped offering sports contracts in the state. Michigan regulators say none of the four platforms holds a state license to take sports wagers. Michigan is taking part in Illegal Gambling Awareness Week, which runs November 9 to 13. A new free tool, CheckBeforeYouPlay.org, lets users check whether a gambling site is licensed.
Michigan has now stopped four prediction market platforms from offering sports event contracts to its residents. Polymarket US is the latest, and it must close existing contracts held by Michigan users by November 25.
The Michigan Gaming Control Board (MGCB) said none of the four platforms holds a state license to accept sports wagers. The group includes Kalshi, Coinbase, Robinhood and Polymarket US.
How the Four Cases Unfolded
The first major step came in September. The Michigan Department of Attorney General secured a preliminary injunction that bars Kalshi from offering sports event contracts to Michigan residents.
Robinhood then reached an agreement with Michigan regulators to stop offering these contracts. In October, Coinbase agreed to do the same for its Michigan customers, including contracts traded on Kalshi.
On October 28, Polymarket US agreed to stop offering new sports-related event contracts in Michigan. A federal court approved the deal, which also requires the company to close existing Michigan contracts by November 25.
The MGCB is working with the Attorney General’s office to pursue platforms that offer sports event contracts without state approval. The regulator has also sent hundreds of cease-and-desist letters to unlicensed online gambling operators.
“Illegal gambling operators want you to believe they’re just another option. They’re not,” said Henry Williams, executive director of the MGCB.
Williams said players on unlicensed sites have