Michigan Court Hands States First Federal Win as Kentucky AG Sues Kalshi, Polymarket, and Coinbase

Prediction markets had one of their roughest 24-hour legal stretches yet on June 17. A federal judge in Michigan ruled that sports prediction market contracts are not CFTC-regulated financial instruments — directly contradicting the only federal appellate ruling on the question — while Kentucky's attorney general filed three separate lawsuits against Kalshi, Polymarket, Coinbase, Robinhood, and Webull for allegedly operating unlicensed sports betting in the state.

Taken together, the two events signal that the legal war over who regulates prediction markets is far from settled, and that the Sixth Circuit Court of Appeals — expected to hear arguments soon — may ultimately force a Supreme Court showdown.

The Michigan Ruling: A Federal Court Sides With States

U.S. District Court Judge Paul L. Maloney of the Western District of Michigan on June 17 denied Polymarket's request for a preliminary injunction that would have blocked Michigan state regulators from restricting its sports event contracts.

More than just denying the injunction, Judge Maloney ruled that Polymarket is unlikely to succeed on the underlying merits. His reasoning was direct: sports prediction market contracts are not swaps under the Dodd-Frank Act of 2010, and therefore the CFTC does not have exclusive federal jurisdiction over them.

"Plaintiff's vision of the scope of derivatives is so vast that it would encompass vast swaths of activity never understood to be associated with the financial industry and instead traditionally associated with core state, as opposed to federal, responsibilities," Maloney wrote.

He went further: "Congress is not so cavalier with the fundamental federalist structure of the government... the Court is convinced that its laws in the wake of the 2008 financial crisis were not aimed at fundamentally redefining the balance between the federal and state governments in ways unrelated to the problems it set out to solve."

The ruling is a direct rebuke of the Trump administration's CFTC, which has aggressively asserted federal supremacy over prediction markets — going so far as to sue states including New Mexico and Wisconsin to prevent them from applying state gambling laws to federally-approved event contracts.

Polymarket filed its Michigan lawsuit in early March 2026 — less than 48 hours after Michigan Attorney General Dana Nessel sued Kalshi. Polymarket claimed it was in "imminent and concrete danger" of enforcement action that would violate its status as a federally authorized designated contract market. Judge Maloney wasn't convinced. The broader case against Michigan regulators will continue, but with Polymarket's injunction denied, Michigan's restrictions remain in force for now.

Polymarket said in a statement that the Kentucky lawsuits — and by extension Michigan's enforcement posture — "go against the CFTC's framework for prediction markets" and that it will address the claims through the legal process.

A Circuit Split Heading Toward the Supreme Court

The Michigan ruling creates a direct conflict with the only federal appellate court that has ruled on prediction market jurisdiction so far.

In April 2026, the Third Circuit Court of Appeals ruled 2-1 for Kalshi in the New Jersey case, finding that sports event contracts listed on a CFTC-registered designated contract market are swaps under federal law — and that the CFTC's exclusive jurisdiction preempts state regulators from blocking them. That ruling was the first time any federal appellate court had addressed the question, and it was a significant win for the industry.

Now, a district court within the Sixth Circuit has reached the opposite conclusion. The Sixth Circuit — which covers federal courts in Michigan, Ohio, Kentucky, and Tennessee — is scheduled to hear its own oral arguments on the jurisdictional question, and its ruling will bind all those states.

The preview inside the circuit is messy. In February 2026, a federal judge in Tennessee sided with prediction markets. In March 2026, a federal judge in Ohio sided with states. And now Michigan, in the same circuit, has come down against CFTC jurisdiction.

If the Sixth Circuit rules differently than the Third Circuit, the case almost certainly goes to the U.S. Supreme Court. Three scenarios:

1. Sixth Circuit affirms CFTC authority — Prediction markets win. Combined with the Third Circuit ruling, nearly every major legal jurisdiction supports federal preemption. States with C&D orders become weaker.
2. Sixth Circuit sides with states — Direct circuit split with the Third Circuit. Supreme Court review becomes likely. Platforms face potential access restrictions in Michigan, Ohio, Kentucky, and Tennessee while litigation continues.
3. Divided ruling — The circuit split sharpens, SCOTUS review becomes probable.

The Sixth Circuit argument is now the single most important legal event on the prediction market calendar.

Kentucky: Two Lawsuits Pointing in Opposite Directions

Michigan wasn't the only courtroom development on June 17. Kentucky Attorney General Russell Coleman filed three lawsuits in Franklin Circuit Court, accusing Kalshi, Polymarket, and online casino operator VGW of running unlicensed gambling platforms in the state.

The suits name:

• Kalshi and its affiliates, including Coinbase, Robinhood, and Webull
• Polymarket and its affiliates
• VGW, the sweepstakes casino company behind Chumba Casino, Global Poker, and LuckyLand Slots

"Kalshi and Polymarket are operating illegal sportsbooks in Kentucky and breaking our laws," Coleman said. "These multi-billion dollar corporations and their legal fictions don't pass the sniff test."

Coleman's office cited striking numbers from the complaint: sports betting accounted for approximately 70% of Kalshi's trading volume in a reviewed 2025 sample period. Across Kalshi's full 2025 contract volume of nearly $23 billion, the AG's office alleged 89% was tied to sports outcomes. The complaints argue that because those contracts closely resemble money lines, point spreads, totals, parlays, and player prop bets available on licensed sportsbooks, they constitute sports wagering under Kentucky law regardless of how they're labeled.

The lawsuits also allege that platforms offer "few or no resources" for problem gambling — a violation of Kentucky regulations that require licensed wagering operators to provide addiction-help resources.

Kentucky is seeking $2,000 per violation of the Consumer Protection Act, plus $10,000 per violation that affected a person age 60 or older.

It's worth noting that this is the second active Kentucky legal battle involving prediction markets — and the parties are reversed in each. As reported earlier this month, a coalition that includes Kalshi, Polymarket, and Crypto.com is suing Kentucky to block the state's 14.25% excise tax on prediction market fees. That suit argues the tax is unconstitutional. Today's AG action argues the platforms are operating illegally in the state in the first place.

A Red State Defying Trump

Kentucky adds a political dimension that other state enforcement actions have lacked. This is a Republican-dominated state whose attorney general is directly opposing a position championed by the Trump White House.

President Trump has been vocally supportive of prediction markets, calling state officials who restrict them "scum." The CFTC under Chair Brian Quintenz and now Chair Michael Selig has sued multiple states — including New Mexico and Wisconsin — to defend federal jurisdiction. The administration's position is unambiguous: prediction markets are regulated at the federal level, full stop.

When a deep-red state like Kentucky files suits against the platforms — naming not just Kalshi and Polymarket but also major fintech institutions like Coinbase, Robinhood, and Webull — it signals that the state-versus-federal fight has moved well beyond blue-state regulatory politics. CoinDesk noted Thursday that the Kentucky action "puts a red state in potential clash with Trump team."

Kentucky also has legislative reinforcement arriving shortly. The Wagering Consumer Protection Act — signed into law earlier this year — takes effect July 15, 2026. That law explicitly bars licensed Kentucky sportsbooks from entering any partnership or revenue-sharing arrangement with Kalshi or Polymarket.

What Traders in Affected States Need to Know

For now, prediction market access in both Michigan and Kentucky is not immediately cut off. Platforms typically continue operating through litigation, seeking injunctions of their own and challenging enforcement through the courts — as they have successfully done in states like New Jersey and Tennessee.

But the trajectory matters:

• Kentucky: The July 15 effective date of the Wagering Consumer Protection Act creates a hard legislative deadline that could prompt more aggressive enforcement. Traders in Kentucky should monitor platform access announcements closely.
• Michigan: Michigan's restrictions remain in place, with the Polymarket case headed to the Sixth Circuit. If you're accessing Michigan-based contracts through Polymarket specifically, verify current availability.
• Sixth Circuit states broadly (Ohio, Tennessee, Kentucky, Michigan): The Sixth Circuit ruling, when it comes, could be binding on all four states simultaneously. A ruling against platforms would likely trigger immediate enforcement efforts across all four.

Platforms have won more legal battles than they've lost so far — the Third Circuit ruling, plus favorable district court decisions in Tennessee and New Jersey — but the string of losses in Ohio and now Michigan shows the outcome is genuinely unsettled.

Nevada remains the only state that has successfully forced platforms to stop offering sports contracts, following a court order that Kalshi said it complied with.

The Bottom Line

June 17 was the clearest signal yet that the legal framework for sports prediction markets in the United States will not be resolved at the district court level. A federal judge in Michigan just ruled the opposite of the Third Circuit. That contradiction now sits inside the Sixth Circuit's docket, waiting to be resolved.

Meanwhile, Kentucky has opened two simultaneous legal fronts — one attacking the platforms' right to operate in the state at all, and one attacking their right to collect revenue under a tax they call discriminatory. The prediction market industry hasn't faced a legal challenge quite like that before.

The Sixth Circuit oral arguments are the next major event to watch. Follow PredictionMarkets.US for coverage as the legal timeline develops.

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Sources: Decrypt (June 17, 2026); Lexington Herald-Leader / McClatchy (June 17, 2026); LEX18 News (June 17, 2026); crypto.news (June 18, 2026); Spectrum News 1 KY (June 17, 2026); Fox56 News Lexington (June 17, 2026); SBC Americas (June 18, 2026); CoinDesk (June 18, 2026); The Block (June 18, 2026).