a16z Briefing: Prediction Markets Break Records for Third Consecutive Week, Weekly Trading Volume Surpasses $14.4 Billion for First Time

Author: Robert Hackett

Compiled by:TechFlow

TechFlow Editor's Note: According to a16z Crypto's data brief, prediction market weekly trading volume surpassed $14.4 billion for the first time last week, hitting a new all-time high for the third consecutive week; at the beginning of the year, this figure was only $5-6 billion. More noteworthy is the non-sports category—politics, economics, geopolitics—which reached $3.6 billion in a single week, larger than the entire market (including sports) for a whole week last year. The World Cup drove up the hype, but growth has long extended beyond betting on soccer.

Last week, prediction market weekly trading volume surged to $14.4 billion for the first time; at the beginning of the year, this figure was still at $5-6 billion. And the previous historical peak (about $10 billion) was just set one week ago.

Aggregated across all platforms, current trading volume is more than 10 times that of a year ago.

Caption: Trend of prediction market weekly trading volume, reached $14.4 billion last week, about $5-6 billion at the beginning of the year

Open interest (referring to the total value of unsettled positions) reached $1.6 billion last week, breaking weekly records for the third consecutive week.

Unlike trading volume, open interest only grows when the rate of new positions opening exceeds the rate of old positions settling. So when this curve goes up, it indicates that the real money bet into these markets is increasing.

Since last autumn, this curve has climbed steadily. During this period, open interest increased by about 8 times, from less than $200 million to $1.6 billion.

Caption: Open interest has increased by about 8 times since last autumn, rising from less than $200 million to $1.6 billion

The World Cup absorbed a lot of attention and capital, and other fields also rose along with it. Non-sports trading volume—covering categories such as politics, economics, geopolitics, current events—totaled $3.6 billion last week across Kalshi and Polymarket. This figure is larger than the total volume of the entire prediction market (including sports) for one week last year.

In July 2025, non-sports weekly trading volume was only around $200 million. Until now, it has increased by about 18 times, and the slope has become significantly steeper this month.

Acknowledgments: Data and charts from Ryan Holloway and Robert Hackett (a16z crypto Feature Editor, Head of Special Projects).