The Spanish government is moving to block Polymarket and Kalshi, saying the two prediction-market platforms might be breaking the law by operating in the country without a gambling license.
The ministry in charge of consumer affairs said it had issued an order to block Polymarket and Kalshi’s websites as a precautionary measure as officials look into possible violations of gambling laws, proceedings that are expected to stretch between three and four months.
Spain’s directorate for gambling regulation said prediction platforms carried gambling risks when these allow users to place wagers on uncertain outcomes, and companies seeking to provide those services need a specific administrative license.
Polymarket and Kalshi didn’t respond to requests for comment.
Polymarket and Kalshi—which allow users to bet on everything from geopolitical events to stock market moves—have made headlines in recent months after a batch of suspicious trades raised concerns of insider trading in Washington.
In April, federal authorities charged a U.S. Army soldier who took part in the operation to capture Nicolas Maduro with using classified information to reap more than $400,000 from bets on the former Venezuelan leader’s ouster.
Last week, James Comer, the Republican chair of the House Oversight Committee, sent letters to Polymarket Chief Executive Officer Shayne Coplan and Kalshi Chief Executive Officer Tarek Mansour requesting documents and information to assess how the platforms verify users’ identities, enforce geographic restrictions and monitor suspicious trading activity.
Polymarket has a data partnership with Dow Jones, the publisher of Dow Jones Newswires and The Wall Street Journal.
Write to Mauro Orru at mauro.orru@wsj.com