Ohio's October 16 deadline passed and most of the ten prediction markets kept trading. Here is who complied, who did not, and what the state does next.
What happened on October 16
The letters gave each recipient fourteen days to confirm in writing that it had stopped offering, facilitating or taking orders for sports event contracts from people located in Ohio. The Commission has not published the replies. What is known comes from a records request by News 5 Cleveland's Morgan Trau, who reported on the evening of October 16 that the Commission had received a commitment from one company, Plus500US, to stop its sports contracts. Trau then opened an account and hit a location block on some sections of the app, though she did not complete a trade, so the geofence's completeness is not established.
For the other nine, the public record is statements rather than compliance. Polymarket and Robinhood each sent near-identical responses that did not answer the station's questions and repeated that they operate under federal rather than state regulation. The rest either did not respond or declined to comment. DeWine said he had personally seen prediction market ads during games since the letters went out. None of the ten has sued Ohio to block the letters, which is the step Kalshi took in October 2025 and Underdog has now taken in seven other states.
| Recipient | Public position at the deadline | Source |
|---|---|---|
| Plus500US | Told the Commission it would stop sports contracts; partial location block observed in app | Commission records via News 5 Cleveland |
| Polymarket | Statement: regulated by the federal government, not the state; no change reported | News 5 Cleveland |
| Robinhood | Statement: regulated by the federal government, not the state; no change reported | News 5 Cleveland |
| Coinbase, Novig, Underdog Predict, ProphetX, Webull, Moomoo, Gemini | No response or no comment; most still operating with no changes | News 5 Cleveland |
| Kalshi (not a recipient) | Spokesperson Dani Lever: rules changing at every state line is why Congress created one federal regulator | News 5 Cleveland |
What Ohio says it will do, and what that costs
DeWine's line was procedural: "You have to actually go out and file these suits," and the state will. Wilson's was substantive: the law is on Ohio's side after the Sixth Circuit's September 25 ruling, the companies' Ohio operations are over "until a higher court rules otherwise," and the state can recover what they made from Ohio residents. That tracks the letters, which threatened a civil penalty equal to the money or value obtained from people in Ohio plus administrative, civil, nuisance or criminal action, and described unlicensed bookmaking as a felony.
The economics explain why nobody rushed to comply. Case Western Reserve's Eric Chaffee told the station that compliance in the way Ohio means it would require a sports gaming licence, a process that can cost upwards of $1 million, after which the operator pays 20 percent tax on revenue and must turn away anyone under 21. Kalshi, Polymarket and Robinhood all accept 18-year-olds. A broker with a small Ohio sports book and a large national one has a simpler option, which is to geofence Ohio the way Robinhood and Coinbase geofenced Michigan by agreement. That is what Plus500US appears to have done. The companies that run their own exchanges have more to lose from conceding the principle, and so far none of them has.
Michigan moves from trading to advertising
Michigan already has what Ohio is asking for: a September 1 preliminary injunction from Ingham County Circuit Judge Rosemarie Aquilina that bars Kalshi from offering, listing or matching sports event contracts in the state and from marketing them, with a $500,000-per-day penalty for violations. On September 29 Attorney General Dana Nessel's office filed a motion to hold Kalshi in civil contempt, reported by DeFi Rate on October 15. The motion does not allege Kalshi took Michigan trades. It alleges Kalshi kept selling the product to Michigan residents: a Michigan Gaming Control Board regulation specialist kept receiving sports promotional emails through a Michigan-based account after the ban; another account holder received targeted emails about upcoming NFL games; a resident who said they had never opened an account reported repeated Kalshi ads after July 1; and a September 20 YouTube ad promoted trading on a Los Angeles Rams game under the label "Kalshi: Trade Football and More."
Kalshi must appear on November 24 to show cause why it should not be held in contempt. The filing matters beyond Michigan because every geofence Kalshi has agreed to or been ordered into, in Nevada, Washington, Michigan and Massachusetts, covers trading. National advertising does not stop at a state line, and if Aquilina finds that a YouTube pre-roll served to a Michigan viewer violates her order, the cost of staying in the other 46 states goes up. Michigan's Gaming Control Board executive director Henry Williams has already framed the exits by Robinhood and Coinbase as operators "halting these activities because they face significant legal consequences."
Tennessee threatens a fantasy licence, and Underdog sues
Tennessee is the other state the Sixth Circuit freed on September 25, and it used the ruling differently. On October 9 the state's Sports Wagering Council sent Underdog a cease-and-desist letter over its sports event contracts, and the letter did something Ohio's did not: it warned that non-compliance could bring revocation of the Tennessee fantasy sports licence held by Underdog Sports, a sister company. On October 13 Underdog Exchange DCM and UDM, which trades as Underdog Predict, sued Attorney General Jonathan Skrmetti and the Council's officials in the Middle District of Tennessee, seeking a declaration that the state's enforcement violates the Supremacy Clause and a permanent injunction. Underdog says the prediction and fantasy businesses are legally distinct. Sportsbook Review's October 16 report counts Tennessee as the seventh state Underdog has sued, after Connecticut, Massachusetts, New Mexico, Ohio, Washington and Wisconsin.
The suit is filed in a circuit that has already held, in Kalshi's own case, that sports event contracts were not shown to be swaps and that the Commodity Exchange Act does not preempt Tennessee's gambling law. A district judge in Nashville is bound by that. Underdog's realistic goal is a record for the Supreme Court, not a Tennessee injunction, and its exposure is larger than Kalshi's because the licence at risk belongs to a business that does not depend on the federal preemption argument at all.
Kalshi's calendar at the Supreme Court
Semafor reported on October 16 that Kalshi is "in no rush" for the Supreme Court to decide whether states can regulate its sports contracts as bets. The docket in Flaherty v. KalshiEX, No. 26-299, bears that out. New Jersey's petition was filed on September 2 with a response due October 8; a motion filed September 18 asked for a month, and the Clerk granted it on September 22, so Kalshi's brief in opposition is now due November 9. The justices have until January to fill this term's argument calendar. In the meantime Kalshi has petitioned the Ninth Circuit, on September 9, and the Sixth Circuit, on October 9, to rehear the decisions against it, both times pointing to the CFTC's October 9 swap-definition rules. Nevada's answer to the Ninth Circuit petition is that the pending regulation "would not change the outcome here."
A Supreme Court litigator working with Kalshi told Semafor the company agrees with its opponents that the justices must eventually decide the question, and that the rehearing petitions and forthcoming rules are "muddying the waters." The American Gaming Association's Rob Lockwood read it differently: Kalshi seems "spooked by the idea of the Supreme Court" taking the case, and sports is "roughly 85% of their total volume." Both readings are consistent with the filings. A company that expects to win wants the case heard before the enforcement map hardens; a company that expects to lose wants time for the CFTC's rules to become final and for a circuit to reverse itself. Kalshi is behaving like the second.
Where the enforcement map stands this morning
| State | Latest step | Date | Effect on sports contracts |
|---|---|---|---|
| Ohio | Deadline for 10 platforms passed; most still trading; governor says suits coming | Oct 16 | Trading continues except Plus500US |
| Michigan | Contempt motion against Kalshi over marketing; hearing Nov 24 | Sep 29 (reported Oct 15) | Kalshi, Robinhood, Coinbase out |
| Tennessee | Underdog sues after Oct 9 cease-and-desist threatening fantasy licence | Oct 13 | Trading continues; Sixth Circuit precedent against platforms |
| Missouri | 30-day cease-and-desist window for six companies closes | About Oct 18 | No compliance statements published |
| Kentucky | Magistrate recommends remanding Polymarket and Kalshi suits to state court | Oct 14 | Trading continues; objections due within 14 days |
| Supreme Court | Kalshi's brief in opposition due | Nov 9 | No change until the Court acts |
Three deadlines fell within 48 hours: Ohio's on October 16, Missouri's on or about October 18, and the Kentucky objection window opening on October 14. None has produced a shutdown. What the week shows is that a cease-and-desist letter, even one backed by a circuit ruling, moves brokers before it moves exchanges, and moves nobody until a court or a licence is on the line. Ohio now has to decide whether to spend the next year suing nine companies one at a time, as DeWine says it will, or wait for the Supreme Court to decide whether it can.
Method and limits
Compliance status at the Ohio deadline is from News 5 Cleveland's October 16 report, including its records request to the Commission and its reporter's own account test on Plus500US; we have not independently tested any platform from an Ohio IP address and we have not seen the companies' written responses, which the Commission has not released. "Most still operating" is the station's characterisation, not a count we verified company by company. Michigan's contempt motion is described from DeFi Rate's October 15 report of the filing; we have not read the motion. The Underdog complaint is described from Sportsbook Review and Legal Sports Report. Supreme Court dates are from the public docket for No. 26-299; the docket does not name the party that filed the September 18 extension motion, though as respondent Kalshi is the only party with a brief in opposition to file. Quotations attributed to Semafor are as that outlet reported them. Nothing here is legal, financial or betting advice.
Frequently asked questions
Did the prediction markets comply with Ohio's October 16 deadline?
Mostly not. News 5 Cleveland reported at the close of business on October 16 that most of the ten recipients were still operating in Ohio with no changes. The one documented exception is Plus500US, which told the Casino Control Commission it would stop its sports contracts; a reporter found a location block on parts of its app. Polymarket and Robinhood issued statements saying the federal government, not the state, regulates them.
What does Ohio say it will do now?
Governor Mike DeWine said the state has to file suits and will, and Attorney General Andy Wilson said Ohio will force compliance if necessary and could recover money the companies made from Ohio sports contracts. The October 2 letters threatened a civil penalty equal to the value obtained from Ohio residents plus administrative, civil or criminal action. No suit had been filed as of October 17.
Why is Kalshi not part of the Ohio deadline?
Ohio is already litigating against Kalshi separately. It wrote to Kalshi in March 2025, fined it $5 million in April 2026, and the Sixth Circuit affirmed the denial of Kalshi's injunction on September 25, 2026. Kalshi has asked the Sixth Circuit to rehear that decision.
What is Michigan's contempt motion about?
On September 29 the Michigan Attorney General asked Ingham County Circuit Judge Rosemarie Aquilina to hold Kalshi in civil contempt of her September 1 injunction, citing promotional emails sent to Michigan accounts and a September 20 YouTube ad for an NFL game. The injunction carries a $500,000-per-day penalty. A hearing is set for November 24.
Has Kalshi asked the Supreme Court for more time?
Yes. The docket in Flaherty v. KalshiEX, No. 26-299, shows a September 18 motion to extend the deadline for the brief in opposition from October 8 to November 9, granted on September 22. Semafor reported on October 16 that Kalshi is in no rush for a ruling while rehearing petitions and the CFTC's new rules are pending.
Related
- Ohio gave 10 prediction markets until October 16 to stop: who got the letter
- Is Kalshi legal in Ohio? The $5 million fine fight
- Is Kalshi legal in Michigan?
- Is Kalshi legal in your state? The 50-state tracker
- Odds converter: cent prices, American odds and the vig
Sources
- News 5 Cleveland, Prediction market platforms ignoring Ohio's legal threats, 16 October 2026.
- LegalSportsBetting, Michigan, Ohio, Kentucky ramp up prediction market attack, 16 October 2026.
- DeFi Rate, Michigan wants Kalshi held in contempt as state crackdown moves beyond trading, 15 October 2026.
- Sportsbook Review, Underdog sues Tennessee as state threatens fantasy sports license, 16 October 2026.
- Semafor, Kalshi in no rush for Supreme Court ruling in fight with states, 16 October 2026.
- Supreme Court of the United States, Docket No. 26-299, Flaherty v. KalshiEX, entries through 8 October 2026.
- Covers, Ohio sends cease-and-desists to 10 prediction market companies, 5 October 2026, for the terms of the letters.
18+ only. This page reports published regulatory letters, court filings and public statements. It is not legal, financial or betting advice. If gambling stops being fun, help is available at 1-800-GAMBLER.