Kalshi & Polymarket: $5.7B Wagered on the World Cup Final

Spain are world champions: Sunday’s 1-0 extra-time win over Argentina brought an end not only to the 2026 World Cup, but also to what was likely the biggest gambling event in history. According to a report by the New York Times, more than $5.69 billion in bets on the outcome of the final were riding on the prediction market platforms Polymarket and Kalshi before kickoff. Anyone who had backed the European champions could celebrate a payout after Ferran Torres’ winning goal in the 106th minute – at the very moment when more and more countries and US states are blocking the platforms or dragging them into court.

And the betting went far beyond picking the world champion. The platforms also hosted millions in wagers on third place, the Golden Boot for the tournament’s top scorer, on what TV commentators would say – and on whether this would be the final tournament for Argentina captain Lionel Messi, whose team missed out on a title hat-trick.

Trading Volumes Quadrupled, App Downloads Exploded

The World Cup turned into a growth engine for the two US platforms. In June, total betting volume on Polymarket and Kalshi surpassed the $50 billion mark for the first time, according to data from crypto data tracker Dune Analytics – up from roughly $2 billion in the same month a year earlier. Chad Beynon, gaming analyst at Macquarie, estimates that the tournament roughly quadrupled monthly trading volumes across both platforms and exceeded every projection.

User numbers surged during the tournament as well: in the week the World Cup kicked off, the Kalshi app was downloaded nearly 270,000 times, according to Apptopia data – compared to around 60,000 downloads two weeks earlier. Both platforms, which earn revenue by collecting fees on every bet, poured money into marketing around the tournament: Polymarket ran a campaign featuring music producer Rick Rubin and rapper Future, while Kalshi became an official FIFA partner through a deal with the World Cup’s existing prediction market partner, ADI Predictstreet – complete with pitchside branding and TV spots.

The tournament itself played into the platforms’ hands: with 48 teams and 104 matches, the 2026 World Cup was bigger than ever, and it coincided with growing interest in soccer in the United States, one of the host countries.

Big Tech and the Betting Industry Are Piling In

The success has not gone unnoticed: according to the NYT, Meta CEO Mark Zuckerberg has directed employees to build a prediction markets app of their own. Traditional betting operators like FanDuel and DraftKings now offer their own prediction markets, as does crypto exchange Gemini, and Trump Media & Technology Group, US President Donald Trump’s social media company, has announced plans for prediction markets as well. Kalshi is now valued at around $22 billion, Polymarket at roughly $15 billion.

But the Wave of Bans Is Rolling: US States Are Suing

Alongside the boom, however, regulatory headwinds have been mounting – on both sides of the Atlantic. In the US, more than a dozen states have filed lawsuits against Kalshi and Polymarket. At the heart of the dispute: the states view the platforms’ sports contracts as plain unlicensed sports betting that violates local gambling laws. The platforms, in turn, point to their status as exchanges for event contracts regulated by the federal CFTC – arguing that federal law applies and that the states have no jurisdiction.

In Michigan, that line of defense collapsed right in the middle of the World Cup: Attorney General Dana Nessel had sued Kalshi in March, alleging the company was offering sports betting “under the guise of trading event contracts” without a license from the Michigan Gaming Control Board. Kalshi’s attempt to move the case to federal court failed in late June – and shortly afterwards, a judge issued a temporary restraining order forcing Kalshi to suspend sports contracts for users in Michigan while the tournament was still underway. Nessel has described the business model as unlicensed and predatory. Nevada had already secured a similar order in March, Massachusetts is also taking action against the platforms, and New York’s gaming commission sent a cease-and-desist letter. Notably, the CFTC recently threw its weight demonstratively behind Kalshi, claiming exclusive jurisdiction – a full-blown turf war between federal and state authorities that will likely only be settled by the highest courts.

Europe: Blocks from Spain to Hungary – and a Grey Zone in Austria

The picture in Europe is similar – except that here, entire countries are cutting off access. Of all places, Spain, home of the new world champions, became the first EU country to move against both platforms simultaneously in late May: gambling regulator DGOJ had the websites of Polymarket and Kalshi blocked nationwide via internet providers and opened sanction proceedings, because both operate without the required gambling license – and, in the authorities’ view, lack sufficient identity checks and minor-protection mechanisms. Spanish fans, in other words, officially couldn’t even bet on their own team’s title run.

Back in January, Portugal and Hungary had already blocked Polymarket – in Portugal partly on the grounds that betting on political events is fundamentally prohibited under national law. In France, Polymarket is only accessible in “view only” mode, and Belgium, the Netherlands and Poland have blocked access as well. In Germany, the joint gambling authority of the federal states (GGL) classifies the platforms as illegal gambling, since they hold no license under the country’s State Treaty on Gambling.

And Austria? There is no active block here yet, but the legal situation is restrictive all the same: the Austrian Gambling Act provides for a state monopoly, and neither Polymarket nor Kalshi holds an Austrian license. Using the platforms thus falls into a classic grey zone of online gambling.

Gambling or Financial Product? The Unresolved Fundamental Question

The common denominator of all these proceedings is an unresolved fundamental question: are prediction markets financial derivatives – or simply a new wrapper for online betting? The platforms present themselves as information markets whose prices reflect the collective assessment of how likely future events are. European regulators, for the most part, see gambling that requires licenses, player protection and age verification. A unified EU framework is missing: the crypto regulation MiCA does not cover prediction markets, which is why each member state currently applies its national gambling law – a regulatory patchwork.

On top of that come repeated allegations of insider trading: several cases in which insider knowledge was allegedly used for profits on the platforms have further fueled the criticism. The World Cup record is more likely to increase the pressure on regulators than ease it – because the bigger the volumes, the louder the question of why the world’s biggest “betting shops” operate without a gambling license in so many places.