Prediction markets hit record volume in September as 15-state sportsbook handle stays flat

Across 15 US states, sportsbook handle came to roughly $11.11 billion in September, an estimated 0.3% lower than a year earlier, while prediction markets posted record trading volumes as the NFL and college football seasons began, according to an analysis published by Gambling Insider.

For affiliates and operators, the data does not show that prediction markets are taking customers from sportsbooks, nor that they are not.

What happened

The 15-state sample showed seven states with year-over-year increases in handle, seven with declines, and Iowa virtually unchanged. Handle rebounded substantially from August, which followed a weak month for the sector.

On the prediction-market side, TickerTracker data cited by Gambling Insider showed Kalshi's notional volume in September at $60.28 billion, a 56.4% rise on August. Trading on four major exchanges totalled $75.5 billion. Prediction Frontier's Q3 report put the combined notional volume of Kalshi, Polymarket, Polymarket US and Novig at $179.6 billion for July to September, an 84.3% increase on the previous quarter. September's $75.5 billion was the largest monthly total in its dataset.

Key figures cited:

• Kalshi, September (TickerTracker): $60.28 billion notional volume, with combos at $34.98 billion (58%) and straight sports contracts at $15.03 billion (24.9%).
• Kalshi, September (Prediction Frontier): about $60.7 billion notional volume, equal to $14.7 billion in dollars paid.
• Q3 (Prediction Frontier): the $179.6 billion in contracts traded cost traders $56.1 billion.
• Macquarie analysts: US taker-side volume of approximately $20.1 billion in September, of which roughly $17 billion was linked to sports.

TickerTracker recorded October Kalshi notional volume at $95.42 billion, up 54.2% from its September estimate.

Notional volume values each contract at its $1 settlement value whatever the price paid, so it is not directly comparable with sportsbook handle. Gambling Insider also noted that Kalshi's platform-wide figures cannot be set against results from only 15 states.

Sportsbook revenue diverged from handle. New York reported $159.4 million in gross gaming revenue, down 17.7% despite a 5% rise in handle, and its hold fell from about 8.47% to 6.64%. In New Jersey, sports wagering revenue dropped 14.3% to $77 million, with volume down 3.6%. In Pennsylvania, taxable sports wagering revenue rose 50.5% to $44.7 million, while volume fell 6.1%. Ohio's revenue increased 12.8% to $87.7 million, even though handle dropped 2.2%.

Why it matters

Affiliates and operators should avoid attributing September revenue changes to prediction-market competition without checking hold first. The state figures show revenue moving independently of handle, and Gambling Insider said changes in betting outcomes and margins can affect revenue regardless of demand.

Marketing teams comparing prediction-market volume with sportsbook handle will need to account for the different metrics. Notional volume and dollars paid give very different pictures of scale, and the gap between $60.7 billion and $14.7 billion for Kalshi in September illustrates this.

The AGA noted that, excluding June and July, monthly handle had declined year over year since December 2025, so flat September handle could indicate stabilisation or a continued slowdown. Gambling Insider said the figures do not indicate whether prediction markets are drawing in new users, cannibalising sportsbooks or both.

The composition of Kalshi's volume, with combos at 58% in September and 67.6% in October according to TickerTracker, suggests that parlay-style products are a major driver of activity. That is likely to be of interest to operators whose sportsbook margins depend on similar bet types.

What's next

Gambling Insider pointed to third-quarter earnings from DraftKings and Flutter Entertainment as a possible indicator, though it noted that both have mostly confined their sports event contracts to states without traditional sports betting, so results may give only a partial picture. October sports betting figures, once available, could show a second month of football-season trends.