TLDR Detroit plans to file an amicus brief in the Coinbase vs. Michigan prediction markets case, becoming the first U.S. city to enter such litigation The city is home to three commercial casinos that generated over $100 million in monthly revenue in early 2026 Coinbase filed suit after partnering with Kalshi, arguing Michigan gambling laws shouldn’t apply to federally regulated event contracts Michigan’s attorney general has also taken enforcement action against Kalshi, Polymarket, and Robinhood Baltimore recently sued six sweepstakes casino operators, showing a broader trend of cities getting involved in gaming enforcement
Detroit is set to become the first U.S. city to step into the legal fight over prediction markets. The city plans to file an amicus curiae brief in the case between Coinbase and Michigan state officials.
According to a March 26 filing, Detroit has asked for permission to submit its brief by April 3. The move signals that the city believes it has a direct stake in how prediction markets are regulated under state law.
Detroit is one of Michigan’s biggest gaming hubs. The city is home to three commercial casinos that are regulated by the state.
Those casinos brought in more than $100 million in monthly revenue in both January and February of this year. The state collected over $24 million in taxes from those operations during that period.
The city may view unregulated prediction market platforms as a threat to its established casino industry. As these platforms begin to look more like traditional betting products, local governments with ties to gaming revenue are paying closer attention.
Coinbase and Kalshi at the Center of the Michigan Case
Coinbase is at the heart of this legal dispute. The company filed a lawsuit seeking to stop Michigan officials from applying state gambling laws to federally