Reports / September 2025
Monthly report
September 2025: $4.65B traded on prediction markets
Notional volume across 4 exchanges was $4.65B, +131% from August. Kalshi led with a 61.6% share. The busiest day was Sun Sep 28, 2025, at $370M.
Exchanges
Ranked by the month's volume.
| # | Exchange | Volume | Share | vs prior month |
|---|---|---|---|---|
| 1 | Kalshi | $2.86B | 61.6% | 3.3× |
| 2 | Polymarket | $1.65B | 35.5% | +49% |
| 3 | Crypto.com | $132M | 2.8% | opened Aug 5 |
| 4 | ForecastEx | $6.2M | 0.1% | +42% |
What traded
At exchanges that publish a split.
Sports, single-leg 89%Combos (parlays) 0%Non-sports 11%
Daily average: $155M over 30 days
Busiest days
- Sun Sep 28, 2025: $370M
- Sat Sep 27, 2025: $325M
- Sun Sep 21, 2025: $297M
- Sun Sep 7, 2025: $254M
- Sun Sep 14, 2025: $251M
September 2025: questions
How much volume did prediction markets trade in September 2025?
$4.65B in notional volume across 4 exchanges, up 131% from August. That is $155M a day on average.
Which prediction market had the most volume in September 2025?
Kalshi. The top three were Kalshi ($2.86B, 61.6%), Polymarket ($1.65B, 35.5%), Crypto.com ($132M, 2.8%).
How much prediction market volume was sports in September 2025?
89% at the exchanges that publish a split, including <1% in combos (parlays). Non-sports markets were 11%.
Notional volume: contracts traded × each contract's payout, from each exchange's own daily report. Download every day as CSV · Methods · All reports