Wisconsin Sues Prediction Markets Over Sports Betting Contracts
TL;DR
Wisconsin Attorney General Josh Kaul has filed lawsuits against Kalshi, Polymarket, Robinhood, Crypto.com, and Coinbase, claiming their prediction market offerings are illegal gambling. The lawsuits aim to ban sports-related event contracts under state law amid increasing regulatory scrutiny.
Key points
- Wisconsin Attorney General Josh Kaul has filed lawsuits against several prediction market platforms.
- The lawsuits claim these platforms facilitate illegal gambling in Wisconsin.
- Kalshi generates over $1 billion annually from sports contracts.
Mentioned in this story
KalshiPolymarketRobinhoodCrypto.comCoinbaseJosh KaulLetitia James
In brief
- Wisconsin Attorney General Josh Kaul has filed complaints targeting Kalshi, Polymarket, Robinhood, Crypto.com, and Coinbase over their prediction market offerings.
- The lawsuits seek to ban sports-related event contracts as illegal gambling and public nuisances under state law.
- The move comes amid mounting regulatory pressure on prediction markets. Wisconsin Attorney General Josh Kaul has sued Kalshi, Polymarket, Robinhood, Crypto.com, and Coinbase in Dane County court, alleging their prediction market offerings constitute illegal gambling operations that must cease serving state residents. The complaints seek declarations that offering sports-related event contracts to Wisconsin customers violates Wis. Stat. § 945.03(1m) and constitutes a public nuisance, according to court documents.
Wisconsin DOJ is suing Kalshi, Robinhood, Coinbase, Polymarket, , and their affiliates, to halt their alleged facilitation of illegal sports betting, a form of unlawful commercial gambling, in Wisconsin. pic.twitter.com/Jf8PMecXRq
— Attorney General Josh Kaul (@WisDOJ) April 24, 2026 Wisconsin cited the platforms' own marketing as evidence, including Kalshi Instagram ads that billed it as "The First Nationwide Legal Sports Betting Platform," and Polymarket's description of prediction markets as a “platform where people can bet on the outcome of future events.” the filings state. The state alleges Kalshi generates more than $1 billion annually from sports contracts—roughly 90% of its estimated total revenue. Wisconsin's enforcement action mirrors a lawsuit filed Tuesday by New York Attorney General Letitia James against Coinbase and Gemini over similar prediction market offerings. "Gemini and Coinbase’s so-called prediction markets are just illegal gambling operations, exposing young people to addictive platforms that lack the necessary guardrails," James said in a , adding, “My office is taking action to protect New Yorkers and stop these platforms from violating the law.”
Q&A
What are the allegations against Kalshi and Polymarket in Wisconsin?
Wisconsin alleges that Kalshi and Polymarket's prediction market offerings constitute illegal gambling operations and public nuisances under state law.
How much revenue does Kalshi generate from sports contracts?
Kalshi reportedly generates over $1 billion annually from sports contracts, which accounts for approximately 90% of its total revenue.
What other states have taken action against prediction markets recently?
New York has filed a lawsuit against Coinbase and Gemini for similar issues, while Connecticut, Arizona, and Illinois are also facing regulatory actions regarding prediction markets.
