TLDR
- Ohio’s casino regulator warned sports betting licensees that serving prediction markets could hurt their license suitability.
- Licensees and applicants must confirm compliance with the notice by October 30.
- Ten firms, including Coinbase, Robinhood and Polymarket, were ordered to stop offering sports contracts in Ohio by October 16.
- Polymarket sued Ohio in federal court, saying the order violates the Commerce Clause and federal law.
- Governor Mike DeWine has reportedly told the attorney general to begin suing firms that have not complied.
Ohio’s gambling regulator has warned its sports betting licensees that working with prediction market companies could put their licenses at risk. The message comes as Polymarket takes the state to federal court.
The Ohio Casino Control Commission sent the notice to sports betting and fantasy contest licensees and applicants. It asks them to confirm they are following the rules by October 30.
Interim executive director Andromeda Morrison shared the update with the seven-member Commission on Wednesday. She said companies that keep supporting “unregulated and unlicensed gaming through prediction markets” may hurt their future suitability.
What the Notice Says
The notice targets companies that provide services to firms offering sports-event contracts in Ohio without a state license. These services include liquidity, market making, integrity monitoring, equipment, data security and other technology work.
The Event Horizon newsletter first reported the notice. The Commission said it was deeply concerned by reports that some licensees still work with unlicensed operators.
According to the notice, supporting illegal gambling reflects on a licensee’s character and reputation. It also said that “maintaining suitability is a continuing obligation of licensure.”
Morrison said the notice follows earlier guidance the Commission issued in August 2025. She said the agency has long held that prediction markets offering sports contracts operate outside Ohio law.
The U.S. Court of Appeals for the Sixth Circuit ruled that Ohio could enforce its gaming laws against Kalshi. After that ruling, the Commission sent cease-and-desist letters to 10 prediction market companies.
The companies were Underdog, Gemini Titan, Coinbase, Prophet X, Novig, Robinhood, Polymarket, Plus500, Moomoo and Webull. They were ordered to stop offering sports-event contracts in Ohio by October 16.
Morrison said the Commission has had productive talks with several of these companies. She did not name them and said the issues remain under investigation.
Polymarket Lawsuit and Governor’s Response
Polymarket responded by filing a lawsuit in the U.S. District Court for the Southern District of Ohio. The company says the letter violates the Commerce Clause of the U.S. Constitution and is preempted by the federal Commodity Exchange Act.
The 46-page complaint notes that offering sports gaming in Ohio without a license is a felony. It argues few licenses are available and they mostly go to companies with an in-state presence.
Polymarket said that even with a license, its operations would be limited to people physically in Ohio. Its attorneys called the rules “discriminatory balkanizing measures.”
The company is asking the court for a preliminary and permanent injunction against the state. The case challenges the constitutionality of Ohio’s sports betting rules.
Morrison said the Commission is reviewing the complaint with the attorney general’s office. “We will vigorously defend Ohio’s sports gaming laws,” she said.
Republican Governor Mike DeWine has reportedly told Attorney General Andy Wilson to begin suing the 10 prediction market operators that have not complied. “The law is very clear. The court decisions have been very clear,” DeWine told the Statehouse News Bureau.
