Prediction Markets Hit Record $123.6B Volume in October 2026

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Prediction markets saw record activity in October 2026, with $123.6B traded, $22.7B in cash paid, and 644M trades executed across platforms like Kalshi and Polymarket.

Prediction markets experienced their largest month on record in October 2026, with notional trading volume reaching $123.6 billion. This figure represents a 58% increase from September 2026 and is 1.5 times the combined total of all trading activity in 2024 and 2025, which amounted to $82 billion. Even when measured by the more conservative metric of cash paid for contracts, October’s $22.7 billion surpassed the entirety of 2025’s $20.9 billion.

October 2026 Sets Records Across Key Metrics

In addition to the headline trading volume, almost every major metric in prediction markets hit all-time highs during October. The number of trades executed reached 644 million, up 36% from the previous month, while open interest rose 42% to $3.1 billion. Fees collected by platforms totaled $647 million, a 27% increase from September.

Kalshi and Polymarket, two of the leading platforms in the space, saw significant traffic growth as well. Kalshi recorded 28 million site visits in October, while Polymarket attracted 38 million, putting them on par with major media outlets like Bloomberg and Politico, according to Similarweb data.

Context Behind the Growth

The surge in activity can be attributed to heightened interest in binary event contracts, which allow traders to speculate on specific outcomes. Football-season parlays reportedly accounted for 67.6% of Kalshi’s October volume, with most contracts priced below one cent. This highlights the distinction between the $1 face value of contracts and the actual dollars committed by traders.

For comparison, the third quarter of 2026 saw $179.6 billion in contracts traded across Kalshi, Polymarket, Polymarket US, and Novig, with $56.1 billion in cash paid. October’s performance builds on this momentum, with Kalshi alone contributing approximately 80% of the month’s total volume, according to separate reports.

Implications for Prediction Markets

The record-breaking activity underscores the growing prominence of prediction markets as both financial instruments and media properties. As platforms like Kalshi and Polymarket continue to attract institutional and retail participants, their role in facilitating event-based speculation is likely to expand further. October’s performance also highlights the importance of distinguishing between different measures of market size, such as notional volume, cash paid, and open interest, to accurately assess the sector’s growth.