Market forecast: December trading volume reaches $18.8 billion, setting a new monthly record high

The prediction market has drawn a perfect conclusion in 2025. Driven by a surge in interest from both institutions and retail investors in event-based forecasting, platforms like Kalshi and Opinion Labs achieved a record-breaking spot trading volume of $18.8 billion in December.
Data from analytics platform Artemis shows that trading volume steadily increased throughout the year, rising from less than $1 billion in January to a peak in December, reflecting that prediction markets are increasingly viewed as tools for hedging risks, measuring election, economic, and pop culture sentiment. Kalshi and Opinion Labs each contributed $6.7 billion, accounting for about 36% of the total; followed by Polymarket ($5.3 billion), Limitless ($672 million), and Myriad ($13.8 million).
This milestone highlights the evolution of prediction markets from niche betting venues to mainstream financial instruments. According to forecasts by research firms like Eilers & Krejcik, their annual trading volume could reach $40 billion in 2026 and approach $1 trillion within a decade.
Kalshi, as a regulated centralized platform in the United States, surpassed Polymarket in weekly trading volume at the end of the year. In the week ending December 21, Kalshi’s trading volume reached $2.3 billion, nearly double that of Polymarket; integration with exchanges like Coinbase and Robinhood significantly boosted its popularity.
Analysts attribute this boom to clearer US regulation and technological advancements supporting real-time sentiment pricing. A market observer posted on X: “This is not noise, but ‘adoption’.” He pointed out that prediction markets are transforming into “real-time sentiment engines,” rivaling the $300 billion global sports betting industry.