State of Prediction Markets - Q3 2026

Some headline numbers:

💳 According to data from American Spend, the 11 states without legal sports betting are home to a third of US adults, but accounted for 55% of Kalshi's card deposits in September 2026.

🎓 In card spending observed in American Spend's data, 18 to 24 year olds account for 30% of Kalshi's card deposits, about twice their share at DraftKings and FanDuel.

📈 Kalshi and Polymarket US now take 11% of card deposits against betting apps in the states in total, up from 3% in Q1 2026, according to data from American Spend.

🗺️ Kalshi's share of US prediction-market search demand rose from 23% to 34% in one quarter, with gains in all 50 states, according to Blask.

📊 $194.1Bn in notional volume, the biggest quarter ever and up 75% on Q2.

🇺🇸 US-regulated exchanges took 89% of notional volume, up from 69% in Q2.

🎯 Parlays (44%) overtook sports (39%) as the biggest share of US notional volume.

We unpack the numbers and headlines behind prediction markets in Q3 2026.