Kalshi and Polymarket Reach $1.4 Billion Monthly Trading Volume
Prediction markets Kalshi and Polymarket jointly recorded $1.44 billion in trading volume in September, with Kalshi surpassing Polymarket’s market share through a strategic partnership with Robinhood that expanded retail access.
Fact Check
The evidence strongly confirms the statement. Source 3 reports that Kalshi's trading volume reached $1.3 billion in September 2025. This figure for Kalshi alone nearly meets the $1.4 billion threshold. Given that other sources state Polymarket has previously surpassed $1 billion in monthly volume (Source 2) and that its trading volume remains 'close' to Kalshi's (Source 10), their combined monthly total easily exceeds $1.4 billion.
- Reference: 1
Summary
In September, prediction markets Kalshi and Polymarket reported a combined $1.44 billion in trading volume. Kalshi gained a 60% market share, overtaking Polymarket for the first time. This surge is attributed to Kalshi’s partnership with Robinhood, which provided access to a large retail user base and significantly boosted activity on the platform.
Terms & Concepts
- Prediction Market: A marketplace where participants trade contracts tied to the outcome of future events, with prices reflecting collective probabilities.
- Trading Volume: The total value of transactions conducted over a specific period, often used as a metric of market activity.