Wisconsin Federal Judge Backs Ho-Chunk Nation in Bid to Bar Kalshi Sports Contracts Under IGRA

A federal judge in Wisconsin has concluded that the Ho-Chunk Nation is likely to prevail in its effort to stop prediction-market operator Kalshi from offering sports event contracts on the tribe's Indian lands under the Indian Gaming Regulatory Act (IGRA), marking what appears to be the first federal IGRA ruling to side with a tribe against Kalshi. U.S. District Judge William M. Conley issued the decision on May 11, 2026, finding a "likelihood of success" on the tribe's IGRA claim, Bloomberg reported. The Ho-Chunk Nation, a federally recognized tribe, sued Kalshi Inc., KalshiEX LLC, Robinhood Markets Inc., and Robinhood Derivatives LLC last August in the U.S. District Court for the Western District of Wisconsin. The Wisconsin ruling breaks from an earlier outcome in California. In November 2025, U.S. District Judge Jacqueline Scott Corley in the Northern District of California denied a temporary restraining order sought by Blue Lake Rancheria, Chicken Ranch Rancheria of Me-Wuk Indians, and Picayune Rancheria of the Chukchansi Indians, holding they had "not met their burden of showing a likelihood of success on their IGRA claim." That decision is now on appeal at the Ninth Circuit. In Wisconsin, the Ho-Chunk Nation moved for a preliminary injunction in December 2025 to block Kalshi and Robinhood from offering sports event contracts to users on tribal lands while the case proceeds. Sixteen tribes filed an amicus brief in support. The complaint also includes a Racketeer Influenced and Corrupt Organizations (RICO) Act claim describing Kalshi's sports event contracts business as a "Gaming Racket," along with false advertising allegations. Trial is set for May 24, 2027, before Judge Conley. Kalshi has argued in the Wisconsin case that its status as a CFTC-regulated designated contract market (DCM) preempts IGRA. Its lawyers point to the 2006 Unlawful Internet Gambling Enforcement Act exemption for DCM-traded contracts from the federal definition of a "bet or wager," and to the CFTC's self-certification process for new event contracts under the Commodity Exchange Act. The arguments track positions Kalshi advanced successfully in earlier enforcement matters before Judge Corley. The federal fight in Wisconsin unfolds alongside a state-level crackdown. On April 23, 2026, Wisconsin Attorney General Josh Kaul filed three parallel lawsuits in Dane County Circuit Court against Kalshi and Robinhood, Polymarket, Crypto .com (operating as Foris Dax Markets), and Coinbase, alleging they facilitated sports betting in violation of Wisconsin's Class I felony gambling statute. Kaul said in a virtual press conference that "thinly disguising unlawful conduct doesn't make it lawful" and called for the companies to be "shut down" from offering sports-related event contracts to Wisconsin customers. The CFTC later sued Wisconsin, along with four other states, alleging they interfered with federal authority over derivatives markets. Kalshi had not publicly commented on Conley's ruling as of publication. The decision adds to a patchwork of early federal outcomes for Kalshi's sports event contracts: the company holds an injunction in New Jersey that was affirmed by the Third Circuit, has lost similar bids in Maryland, and saw its Nevada injunction dissolved on review.