Open interest in prediction markets surged to an unprecedented $1.48 billion in the week ending June 15, setting a new record for the second consecutive week. This growth highlights the increasing momentum in the sector, particularly driven by sports contracts that spurred trading activities. During this week, trading volume also hit $10.8 billion, marking yet another historical peak for the industry.
As reported by a16z crypto, open interest, which evaluates the value of active contracts in the market, has increased nearly sixfold over the past year. This measure indicates the capital traders are maintaining at risk as opposed to settled contracts.
“The recent growth signifies a sixfold increase year-over-year, showcasing how users are opting for longer-term financial strategies and how prediction markets are evolving into stable market infrastructures,” noted a16z in their market analysis.
The remarkable open interest growth was largely fueled by major platforms like Kalshi and Polymarket, with smaller platforms such as Opinion, Limitless, and Myriad contributing a smaller segment of the total activity.
Beyond open interest, weekly notional volume soared to a staggering $12.2 billion, while fees collected by prediction market platforms reached an all-time high of $76.8 million. Additionally, the number of active users peaked at a record 426,975 during this time frame.
Sports-related contracts emerged as the primary catalyst for this increased activity, accounting for $5.8 billion in notional volume, nearly half of the overall market trading. This segment consistently delivered the highest volume on both Kalshi and Polymarket.
The upcoming 2026 FIFA World Cup significantly bolstered participation, drawing in new users and stimulating activity. Reports indicated that some traders placed wagers worth seven figures on individual matches, with one trader reportedly earning a staggering $9.24 million in just a day.
According to independent market data, prediction markets registered a weekly trading volume of $10.8 billion for the week ending June 15, marking another historic high for the sector.
This increase signifies a dramatic uptick compared to the previous year, when a typical week in prediction markets saw trading volumes hovering around half a billion dollars, with even peak weeks falling below the $1 billion mark.
Industry analysts attribute this latest flurry of activity to a convergence of high-profile global events, including the SpaceX IPO, a U.S.-Iran peace agreement, the NBA Finals, the Stanley Cup Finals, and the kickoff of the FIFA World Cup.
Data indicates that prediction markets are successfully attracting a diverse user base beyond just conventional political forecasting, with an increasing number of traders engaging in markets related to sports, economics, culture, and cryptocurrency events.