Prediction Markets Hit Record $10.8B Weekly Volume

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Prediction Markets Hit $10.8 Billion Weekly Volume and $1.48 Billion Open Interest – Sports Contracts Drive Record Activity Across Platforms

Key Takeaways

Prediction market open interest reached a record $1.48 billion in the week ended June 15.
Weekly trading volume climbed to an all-time high of $10.8 billion, with notional volume at $12.2 billion.
Sports-related contracts generated $5.8 billion in notional volume, nearly half of total activity.
Active users rose to a record 426,975, while weekly platform fees hit $76.8 million.

Open Interest Rises to $1.48 Billion as Capital Remains Locked in Markets

Prediction market open interest climbed to $1.48 billion in the week ended June 15, marking the second consecutive weekly record. Open interest measures the total value of outstanding contracts that remain active and have not yet been settled. The metric reflects how much capital traders continue to keep at risk in ongoing positions.

According to a16z crypto, open interest has increased roughly sixfold over the past year. The firm noted that this growth indicates users are maintaining longer-term financial positions rather than closing out contracts quickly. The record level was driven largely by activity on leading platforms Kalshi and Polymarket. Smaller venues such as Opinion, Limitless and Myriad accounted for a comparatively smaller share of overall activity.

The sustained rise in open interest signals that more capital is staying within prediction market ecosystems at any given time, increasing the scale of active exposure across contracts tied to real-world events.

Weekly Trading Volume and Notional Volume Reach New Highs

In addition to record open interest, weekly trading volume reached $10.8 billion, another all-time high for the sector. Separate market data for the same week confirmed the $10.8 billion figure, highlighting a sharp acceleration compared to the previous year. A year earlier, a typical week generated around half a billion dollars in trading volume, and even the busiest weeks remained below $1 billion.

Weekly notional volume, which reflects the total value of all contracts traded regardless of settlement status, climbed to $12.2 billion. This figure underscores the overall scale of transactions flowing through prediction market platforms during the period.

Platforms also recorded $76.8 million in weekly fees, setting another industry record. Fee generation reflects the direct revenue impact of higher trading activity and increased participation.

Sports Contracts Account for Nearly Half of Market Activity

Sports-related contracts emerged as the primary driver of recent growth. The category generated $5.8 billion in notional volume, representing nearly half of total trading during the week. Sports was the largest source of volume on both Kalshi and Polymarket.

The ongoing 2026 FIFA World Cup contributed significantly to the surge in participation. The tournament attracted new users and increased activity among existing traders. Some participants reportedly placed seven-figure wagers on individual matches, while one trader reportedly generated $9.24 million in profits in a single day.

Beyond football, other high-profile sporting events also contributed to the overall spike in activity. The NBA Finals and the Stanley Cup Finals were cited among the global events that supported higher trading volumes.

Broader Event Coverage Expands User Participation

Industry observers attributed the record activity not only to sports but also to a range of major global developments. These included the SpaceX initial public offering and a US-Iran peace deal, alongside sports championships and the opening stages of the FIFA World Cup.

The data suggest that prediction markets are attracting a broader user base beyond traditional political forecasting. Traders increasingly participate in contracts tied to sports, economics, culture and cryptocurrency-related events. This diversification of topics corresponds with the rise in active users, which reached a record 426,975 during the week.

The combination of high-profile global events and expanding thematic coverage has contributed to sustained engagement across multiple categories. Compared with the previous year, when weekly volumes typically stood around half a billion dollars, current figures reflect a substantial increase in both scale and frequency of trading activity.

Platform Concentration and Market Structure

While several platforms operate in the sector, the latest data indicate that Kalshi and Polymarket account for the majority of open interest and trading activity. Smaller platforms including Opinion, Limitless and Myriad represent a more limited share of the market.

The concentration of liquidity on leading venues may influence where users choose to place trades, as higher activity levels generally correspond with deeper markets and greater contract availability. At the same time, the participation of multiple platforms shows that activity is distributed across a broader ecosystem rather than confined to a single operator.

Our Assessment

The latest data show that prediction markets reached record levels in open interest, trading volume, notional volume, fees and active users in the week ended June 15. Growth has been driven primarily by sports-related contracts, particularly those linked to the 2026 FIFA World Cup, alongside other major global events. Compared with the previous year, both capital committed to open contracts and weekly trading volumes have increased severalfold, with leading platforms Kalshi and Polymarket accounting for the largest share of activity.