Kalshi, a prediction market startup, experienced a substantial uptick in activity during the 2026 FIFA World Cup, registering roughly $27 billion in trading volume and attracting about 3 million users over the duration of the tournament, according to a person familiar with the matter. Those outcomes were almost double the platform's internal forecasts, which had anticipated about $13 billion in volume and 1.5 million users.
The World Cup this year expanded to a 48-team format and became the most lucrative in FIFA's history. The tournament opened at Estadio Azteca in Mexico and concluded in New Jersey, where Spain defeated Argentina to claim the title for a second time. Fans used Kalshi and other prediction platforms to translate sporting knowledge into trading activity as match outcomes and tournament narratives unfolded.
Prediction markets such as Kalshi and Polymarket provide a venue for people to wager on the outcomes of discrete events - from sports matches to elections - and have seen increased interest since the 2024 Presidential election. The surge in users and volume from the World Cup has pushed Kalshi more clearly into the mainstream for event-based contracts, reinforcing the commercial potential of that product category.
Business expansion and new market offerings
Earlier in the month Kalshi announced plans to begin accepting wagers tied to the outcomes of clinical trials and FDA regulatory reviews, making drug-development odds publicly available for the first time on its platform. That move signals an expansion of the company's contract types beyond sports and political events into healthcare-related event markets.
Regulatory scrutiny and legal challenges
Despite the surge in trading and users, Kalshi faces a range of legal and regulatory obstacles. Critics argue that prediction platforms operate as illegal gambling enterprises that could foster addictive behavior and be susceptible to insider trading. Kalshi has been involved in litigation with several U.S. states that contend its event contracts violate local gaming laws.
Massachusetts was the first state to seek an injunction against the platform. Washington state also won a court order to block Kalshi after a judge concluded the company's event contracts were likely in violation of state gambling statutes.
Separately, federal regulators are probing potential insider trading tied to activity on Kalshi. The inquiry centers on Gabriel Perez, who has been identified in reports as a longtime teleprompter operator for U.S. President Donald Trump. Two sources familiar with the matter said federal authorities are investigating possible insider trading. Kalshi alerted regulators after detecting suspicious behavior through its onboarding and market surveillance processes and referred the matter to the Commodity Futures Trading Commission.
The combination of rapid user growth and legal pressure creates a complex operating environment for Kalshi. The company has demonstrated a capacity to scale trading volume dramatically during major global sporting events, while simultaneously confronting litigation and regulatory review as it expands into new event categories.