Kalshi adds 3 million users as World Cup trading lifts prediction markets

Kalshi’s World Cup push has turned soccer demand into a major user-growth moment for prediction markets. For retail investors watching the category, the takeaway is straightforward: big cultural events can drive trading activity on event contracts, but keeping those users active after the event is the harder test.

Kalshi told CNBC it added 3 million new users during the 2026 FIFA World Cup. The company also said more than $1.2 billion has traded on contracts tied to the tournament winner, which CNBC reported is a record for a single market on the platform.

A prediction market lets users trade contracts based on whether a future event will happen. In this case, traders bought and sold contracts linked to the outcome of the World Cup, with the market set to close Sunday after Spain and Argentina play in the final.

The World Cup has lifted trading across prediction market platforms, CNBC reported. Vijay Viswanathan, an associate dean of integrated marketing communications at Northwestern University, told CNBC that soccer’s global reach gives the tournament a rare audience size, saying the sport is played in nearly every country and that few events compare with the World Cup’s total addressable market.

Kalshi spent heavily on World Cup visibility

Kalshi has used the tournament to put its brand in front of soccer fans through several partnerships and ads. CNBC reported that Kalshi partnered with ADI Predictstreet, the official prediction market sponsor of the World Cup, on co-branded stadium advertising.

The company also partnered with OpenAI so that Kalshi contract odds appeared when users searched ChatGPT for information about tournament games, according to CNBC. Its soccer-related marketing included ads or partnerships involving Croatian player Luka Modric, longtime Real Madrid coach José Mourinho and Argentina’s national team. CNBC reported that the Argentina tie-up led to Kalshi appearing in an Instagram post by Lionel Messi.

Kalshi CEO Tarek Mansour, who CNBC said plays a central role in the company’s marketing strategy, said the company’s volumes follow major news moments. He told CNBC the World Cup approach centers on reacting creatively to events as they happen. Mansour also said one ad featuring former professional soccer players was conceived, produced and released within 24 hours.

Kalshi also used celebrities outside soccer during the tournament. CNBC reported that the company released an ad with actor Timothee Chalamet in June, around the time he was drawing attention for appearances at New York Knicks games during the NBA Finals, and a spot with Colombian singer J Balvin this month.

Elizabeth Johnson, executive director of the Wharton Neuroscience Initiative at the University of Pennsylvania, told CNBC the non-soccer ads help Kalshi signal that prediction markets can apply beyond sports. Johnson also teaches visual marketing at the university.

Sports contracts remain under scrutiny

Kalshi’s World Cup surge comes as sports event contracts face legal and regulatory pressure. CNBC reported that states argue those products resemble sports betting, an area they regulate. Kalshi supports the federal government’s position that the Commodity Futures Trading Commission, which oversees swaps and derivatives, has exclusive authority over prediction markets.

Mansour rejected concerns about the sports contracts, telling CNBC the pressure is coming from gambling companies worried about protecting established positions.

Brian Sung, a partner in the derivatives and digital assets practice groups at Haynes Boone, told CNBC that Kalshi’s advertising is unlikely to determine how courts rule. He said the marketing could still affect public and political perceptions, since sports account for much of the company’s activity.

The next question for Kalshi is whether the World Cup users stay. CNBC reported that trading has been meaningfully lower on days without World Cup matches than on match days. Mansour told CNBC that Kalshi has seen similar cycles before, with large events lifting volume, followed by a pullback and then renewed activity around other news.

CNBC disclosed that it has a commercial relationship with Kalshi, including customer acquisition and a minority investment.

This story draws on original reporting from CNBC.