Kalshi dominates prediction trading as monthly contract volume reaches $123.4 billion

Prediction markets recorded $123.4 billion in contract trading at face value over 30 days, according to DeFi Rate’s volume tracker. Kalshi accounted for $93.0 billion of that total, placing it well ahead of Polymarket US.

Kalshi captures most of the volume

DeFi Rate put Kalshi’s share at about 76 percent. Polymarket US registered $14.2 billion over the same 30-day period.

The figures measure contracts at face value. That distinction matters when interpreting the headline total: the reported measure is contract trading volume, not a stated amount of cash committed by traders.

Daily activity spans two reporting windows

Trading across venues on October 31 had reached $2.95 billion so far, according to DeFi Rate’s tracker, as summarized in the October 31, 2026 update published at 1:15 PM ET.

The tracker separately recorded $4.7 billion over the last 24 hours. The rolling 24-hour figure and the October 31 total cover different windows and should not be treated as directly equivalent measures of daily activity.

What it means for prediction markets

• Volume is concentrated: Kalshi’s approximately 76 percent share makes its activity central to interpreting the reported market-wide total.
• The measurement matters: The $123.4 billion figure represents contracts at face value, rather than a reported cash-investment total.
• Timing affects comparisons: The $2.95 billion October 31 reading is a partial-day figure, while $4.7 billion covers the last 24 hours.
• Volume is not a forecast: The supplied figures describe trading activity, not contract prices or implied probabilities for particular outcomes.