Key Points

• Kalshi’s US web traffic reached 15.4 million visits in July, up roughly 1,520% from fewer than 1 million visits in August 2025.
• Monthly notional trading volume surged to approximately $40 billion in August from $874 million a year earlier, outpacing the platform’s traffic growth.
• Sports contracts accounted for 83% of Kalshi’s July trading volume as the company faces growing legal challenges over whether its event contracts fall under federal derivatives oversight or state gambling laws.

Kalshi’s US Audience Expands Rapidly

Kalshi’s growth has accelerated dramatically over the past year, with US web traffic rising more than fifteenfold as prediction markets gain wider attention and the platform’s sports-contract business comes under increasing regulatory scrutiny.

According to Similarweb estimates, Kalshi recorded approximately 15.4 million visits from US users in July, compared with just under 1 million in August 2025. That represents an increase of roughly 1,520% in less than a year.

The US also accounted for nearly 80% of Kalshi’s total website traffic in July, compared with 72.8% in August 2025. The figures indicate that the platform’s expansion remains heavily concentrated in the US market, where its prediction contracts have become increasingly prominent.

The surge in traffic comes as Kalshi faces legal challenges over the regulatory classification of its sports-related contracts.

Trading Volume Is Growing Even Faster

User interest has translated into a much larger increase in trading activity.

Kalshi generated approximately $40 billion in monthly notional trading volume in August, compared with $874 million a year earlier, according to prediction-market data from Dune Analytics. The increase represents growth of roughly 4,500% in 12 months.

The broader prediction-market sector has also expanded rapidly. Monthly notional volume across the industry reached approximately $50.7 billion, compared with around $2 billion during the comparable period a year earlier.

At approximately $40 billion, Kalshi represented nearly 79% of the industry’s latest monthly volume, highlighting the platform’s dominant position within the rapidly expanding prediction-market sector.

The difference between traffic and volume growth is notable. While website visits increased roughly fifteenfold, trading volume grew by approximately forty-six times, suggesting that existing users are also becoming significantly more active.

Sports Contracts Drive Kalshi Activity

Sports have become a central component of Kalshi’s trading activity.

Sports contracts represented 83% of the platform’s trading volume in July, according to reported data. That concentration helps explain both Kalshi’s rapid growth and the regulatory pressure surrounding its business model.

Unlike traditional sportsbooks, Kalshi operates its event contracts within the framework of federally regulated prediction markets. State gaming authorities, however, have increasingly challenged whether sports-related contracts should instead be treated as gambling subject to state laws.

The distinction has become one of the most consequential regulatory questions facing the prediction-market industry.

Legal Pressure Grows Alongside Expansion

Kalshi’s commercial expansion has coincided with increasingly intense legal scrutiny.

New Jersey has escalated its dispute with Kalshi to the US Supreme Court, asking the justices to determine whether states can regulate sports contracts offered by prediction-market companies registered with the Commodity Futures Trading Commission.

The case could have consequences well beyond New Jersey. A ruling could help establish whether federal commodities law protects prediction-market operators from state gambling regulations or whether states retain authority over sports-related contracts offered to residents within their jurisdictions.

For Kalshi, the legal outcome could therefore influence the regulatory framework under which a significant portion of its trading activity operates.

Traffic Rises in Restricted Markets

Kalshi has also experienced substantial growth in traffic from jurisdictions where its member agreement currently prohibits users from directly accessing or trading on the platform.

Canada generated approximately 450,000 visits in July, compared with about 50,000 in August 2025. UK visits increased to approximately 296,000 from around 31,000 over the same period.

Despite the increases, both markets represented a smaller proportion of total traffic. Canada’s share declined to 2.3% from 3.8%, while the UK’s share fell to 1.5% from 2.4%.

Kalshi has nevertheless established a separate route into Canada through a partnership with financial services company Wealthsimple. The arrangement provides eligible users access to nearly 4,000 Kalshi contracts through a separate application.

Outlook

Kalshi’s explosive growth demonstrates the rapidly increasing demand for prediction markets, but its expansion is occurring alongside a major regulatory test. The combination of surging trading volume, heavy exposure to sports contracts and growing state-level opposition places the company’s business model at the center of a broader debate over whether event contracts should be regulated as financial products or gambling. The eventual legal