Prediction Market Volume Hits $120.7B, Up 64% in October
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U.S. prediction market trading volume reached $120.73 billion in October 2026, up 64.1% from September, according to DeFi Rate, as sports combo contracts drove record activity across eight reporting exchanges.
Kalshi accounted for most of the increase, generating $98.15 billion in volume and capturing 81.3% of the measured market. Its activity rose by $37.30 billion from September, representing approximately 79% of the sector’s monthly expansion.
Identified combo trading across five exchanges jumped 93.2% to $79.46 billion, compared with $41.13 billion in September. Kalshi contributed $66.86 billion of that October activity, reflecting the growing importance of bundled event contracts.
Separate Artemis data, reported by KuCoin, put October volume at $123.3 billion across 642.9 million trades, a 53.9% monthly increase.
The datasets use different reporting coverage.
October Trading Volume by Exchange
DeFi Rate’s exchange-level figures show growth concentrated among established leaders, although smaller sports-focused platforms recorded faster percentage increases.
Sports Contracts Drive Trading Growth
Artemis data showed football-related parlay products represented 67.6% of Kalshi’s reported volume, highlighting the importance of nominal contract values when interpreting trading activity.
Kalshi counts transactions using the full $1 contract payout rather than the money committed upfront. With most football parlay contracts priced below one cent, headline trading figures can substantially exceed actual capital deployed.
Polymarket US also expanded its identified combo activity to $8.60 billion, while Underdog recorded the fastest overall percentage growth among the eight exchanges.
On October 25, 2026, Novig and Underdog recorded their busiest trading days of the month, processing $208.7 million and $144.6 million respectively.
Election and Cryptocurrency Trading Activity
Election-related contracts generated more than $1.4 billion in trading volume ahead of the U.S. midterms, according to the Artemis figures.
Crypto-related contracts exceeded $3 billion in each of two consecutive weeks, according to the KuCoin report’s main text.
| Exchange | October Volume | September Volume | Monthly Change |
|---|---|---|---|
| Kalshi | $98.15B | $60.85B | +61.3% |
| Polymarket US | $14.77B | $8.70B | +69.8% |
| Novig | $3.27B | $1.45B | +126.1% |
| Crypto.com / Nadex | $2.19B | $1.56B | +40.3% |
| Underdog Exchange | $1.98B | $721.5M | +174.7% |
| ProphetX | $306.3M | $240.7M | +27.3% |
| Gemini Titan | $42.1M | $44.1M | -4.4% |
| ForecastEx | $14.4M | $19.5M | -26.3% |
