Spain temporarily banned the US-based prediction markets Polymarket and Kalshi on Tuesday, as well as its rival Kalshi, arguing that they were operating without a gambling license. The ban will last three to four months, pending a review from the country’s gambling watchdog. The move comes as other bans against Polymarket, in particular, are stacking up around the world. They aren’t all necessarily country-wide: in the United States, Minnesota recently became the first state to ban prediction markets. Nonetheless, questions are growing around these prediction companies, as a growing number of insider trading cases come to light.
Hard Numbers
Another Polymarket ban
Will Fitzpatrick
By Zac WeiszMay 28, 2026
Zac Weisz
Zac reports on global affairs, covering everything from battles between judicial branches and political leaders, to conflicts in Africa, Europe, and the Middle East. With the Trump administration keen to alter the world order, though, there’s a heavy emphasis right now on US politics – an area with which he is intimately familiar. Prior to joining GZERO, Zac was a senior national politics correspondent at National Journal, where he covered the 2024 presidential election from its inception to the dramatic finish, as well as major congressional actions during the Biden administration. Prior to journalism, Zac worked as an economic analyst for Oxford Economics, calculating the impact of various tax policies, and of Britain’s exit from the European Union. Born in London, he currently resides in New York City, where you can find him playing football (the original version) or watching it on television while attempting to cook up a storm.
