A federal judge has approved a procedural agreement in the ongoing dispute between Coinbase and Michigan regulators. This clears the way for Detroit to become the first U.S. city to formally challenge sports-related prediction markets in court.
In a March 26 order, Shalina D. Kumar of the United States District Court for the Eastern District of Michigan signed off on a stipulation jointly submitted by Coinbase Financial Markets Inc. and state officials. The agreement resolves a dispute over recent filings tied to Coinbase’s request for a preliminary injunction and sets a revised schedule for additional briefs.
Detroit looks to file an amicus curiae brief
Potentially the biggest development in the latest order is Detroit’s planned involvement in the case. City officials approached both parties seeking permission to file an amicus curiae brief, a filing that allows a non-party to offer the court additional context, expertise, or legal arguments.
Both sides agreed to the request, and the court’s order allows Detroit to submit its brief by April 3.
If the city ultimately argues against prediction markets, it would be the first time a U.S. municipality has taken a direct legal stance opposing the products. That could provide courts and regulators with a new perspective, particularly on how emerging wagering-style platforms affect communities at the local level.
The City of Detroit is poised to become the first municipality to come out against prediction markets. The Motor City has been granted permission by a federal judge to file an amicus curiae brief in support of Michigan’s opposition to Coinbase’s motion for preliminary injunction. pic.twitter.com/6tMW3YcaBU
— Daniel Wallach (@WALLACHLEGAL) March 27, 2026
Coinbase challenges state enforcement
The underlying lawsuit pits Coinbase against Dana Nessel and members of the Michigan Gaming Control Board, who are being sued in their official capacities.
Coinbase is seeking a preliminary injunction, which is a temporary court order that, if granted, would prevent Michigan from taking enforcement action while the judge considers the broader legal questions in the case. Such injunctions are typically sought when a company argues that immediate regulatory action could cause irreparable harm before the courts have fully resolved the dispute.
Filing dispute leads to revised briefing schedule
The procedural disagreement that prompted the latest order began in February, when Coinbase filed additional materials with the court, including a notice of supplemental authority and a motion requesting permission to respond to a proposed sur-reply from the defendants. The company also attached a lengthy exhibit outlining its planned response.
State officials objected to those filings on March 2, arguing they were improper. After further discussions, however, the parties reached a compromise: the state withdrew its objection and instead agreed to submit a formal response addressing the materials.
Under the court-approved stipulation, that response was due March 27. Judge Kumar’s order formally adopts the agreed terms, putting the revised briefing schedule into effect.
Prediction markets face growing legal scrutiny
The dispute is unfolding against a backdrop of increasing national scrutiny of prediction markets, particularly contracts tied to sports outcomes. In Washington, D.C., bipartisan lawmakers have introduced legislation that would ban sports-related prediction markets, citing concerns that the products function too similarly to unregulated sports betting.
Courts across the country have also begun to issue diverging rulings. Examples of this include a judge in Nevada recently blocking certain event contracts offered by Kalshi, while a federal judge in Arizona declined to grant emergency relief that would have protected similar contracts from potential criminal enforcement.
Together, those decisions have contributed to a patchwork of legal outcomes that leaves the status of prediction markets unsettled across jurisdictions.
Municipal perspective could influence broader debate
Detroit’s anticipated filing could carry weight beyond the immediate dispute between Coinbase and Michigan regulators. Cities are often the first to deal with the social and economic consequences of gambling activity, from problem gambling services to local enforcement concerns.
Detroit could help the court assess the potential community-level impacts of prediction markets as it decides whether Coinbase should receive the temporary protections it is seeking, and, more broadly, how these emerging financial products should be treated under existing gambling and commodities laws.
