Kalshi Adds 3 Million Users as World Cup Fuels Record Trading Volume

The 2026 FIFA World Cup has driven a surge in activity for Kalshi, with the prediction market platform reporting 3 million new users and over $1.2 billion traded on its winner-market contract. The market closed on Sunday after Spain defeated Argentina in the final, marking the highest volume ever recorded for a single market on the platform, according to a CNBC report.

Northwestern University Associate Dean Vijay Viswanathan highlighted the global appeal of football, saying that because the sport is played in virtually every country, “in just terms of the total addressable market, there's really nothing that comes close to the FIFA World Cup.”

Partnerships and Campaigns

Kalshi’s World Cup push included a co-branded advertising deal with ADI Predictstreet, the tournament’s official prediction market sponsor, featuring in-stadium signage. The company also integrated with OpenAI so that its contract odds appear when users search for World Cup matches on ChatGPT. Additional campaigns involved soccer star Luka Modric, former Real Madrid coach José Mourinho, an Argentina national team sponsorship that earned a mention from Lionel Messi on Instagram, actor Timothée Chalamet (tied to the NBA Finals in June), and Colombian singer J Balvin this month.

CEO Tarek Mansour said the strategy relies on speed and relevance: “The most important thing is to enable creativity based on what's happening.” He noted that a recent ad with former soccer players in a scrimmage was produced within 24 hours.

Broader Appeal and Regulatory Tension

Elizabeth Johnson, Executive Director of the Wharton Neuroscience Initiative, observed that the diverse partnerships help Kalshi signal relevance beyond sports fans: “They're seizing this moment to remind people about the ubiquity of what these prediction markets are.”

The company’s sports-event contracts remain controversial. State regulators argue they amount to sports betting, a state-regulated activity, while Kalshi insists the Commodity Futures Trading Commission has exclusive jurisdiction over prediction markets. Mansour dismissed state objections as driven by gambling companies afraid of losing market share.

Retention Challenge Ahead

Traffic has dipped on non-match days, but Mansour expects the pattern to follow previous cycles—a post-event lull followed by renewed interest around future news events. “You have to believe there's not going to be any news after Sunday,” he said. “Maybe, … but the more probable thing is that there's going to be a bunch of things going on in the world, and Kalshi's going to be there to service it.”