Baltimore sues Kalshi and Polymarket, adding Coinbase, Robinhood and Webull
Mayor Brandon Scott and the Baltimore City Council sued Kalshi, Polymarket, Coinbase, Robinhood, and Webull on August 13, alleging illegal sports betting disguised as event contracts. The city claims the platforms violate local consumer protection and gambling laws. Both Kalshi and Polymarket are CFTC-regulated. The suit adds a municipal front to the state-level pressure already hitting prediction market platforms and their distribution partners.
The Baltimore suit names distribution partners, not just platforms. Coinbase, Robinhood, and Webull now face direct consumer-protection exposure for listing sports event contracts they do not themselves design. That reshapes the risk calculus for every broker-dealer and exchange considering similar listings. A city-level loss could embolden other municipalities to file copycat suits, multiplying legal venues beyond the state attorneys general already active. For Kalshi and Polymarket, partner defections become a real risk if settlement costs look cheaper than defense.
Traders holding open sports contracts face fresh geographic uncertainty: a Baltimore injunction would not bind other jurisdictions, but it would signal that municipal courts may join the pile-on. The platforms must now defend on two fronts — state preemption arguments and municipal consumer protection claims — with each front able to void local trading independently. A partner pullout, even without a final judgment, would cut distribution and volume faster than any single platform ruling.
Baltimore becomes the fourth jurisdiction to sue Kalshi or Polymarket over sports contracts this year, after parallel actions by New York, Wisconsin, and Utah.