Macquarie puts September prediction-market taker volume at $20.1B, up 1,079% year over year

September volume reaches $20.1B

Prediction-market taker volume totaled $20.1B in September, up 1,079% year over year, according to Gambling Insider’s account of Macquarie’s Oct. 9 note.

Macquarie put Kalshi’s share of September taker volume at 67%. That places the platform at roughly two-thirds of the reported monthly total.

Sports dominate the reported activity

Sports contracts accounted for about $17B of September taker volume, according to the figures reported by Gambling Insider. Against the $20.1B total, that makes sports the dominant category in the monthly breakdown.

Macquarie also forecast U.S. taker volume of $186.8B for 2026. That is a full-year projection, distinct from the reported September activity.

What it means for prediction markets

• Platform concentration: Kalshi’s 67% share makes its activity central to understanding the September volume figures.
• Category concentration: With about $17B attributed to sports contracts, the headline total should not be treated as evidence of equally strong activity across other categories.
• Forecast versus results: The $186.8B U.S. estimate represents Macquarie’s outlook for 2026, not completed annual volume.