Prediction Markets Post Best Month on Record With $123B Volume, 643M Trades in October

Predictions markets just had its best month on record. According to data from Artemis, monthly trading volume across all prediction markets blew past the $100 billion mark for the first time, reaching $123.3 billion. That’s approximately a 53.9% growth from the previous high set in September. October also saw the number of trades reach a new record of 642.9 million. 

The market share breakup shows that Kalshi drove most of it. The platform drew in $98.2 billion in trading volume over the course of the month, or roughly 80% of the entire sector, and processed 465.5 million trades. Polymarket came in a distant second with $20.2 billion in volume and 148 million trades. While the other smaller platforms took a tiny share of the market, Nadex crossed the $2 billion monthly volume mark and Rothera saw a second consecutive month where volumes crossed $1 billion. 

Football Weekend Pushed Kalshi to Three Straight Weekly Records 

The NFL and college football seasons were a massive catalyst for the record month. Sports was by far the largest category in October. During the month, Kalshi set three back-to-back weekly trading volume records. The largest one came in the week ending October 25 when the platform drew in over $25 billion in volume over seven days. 

A lot of that money moved through combos, Kalshi’s parlay product. Ticker Tracker data shows that, across the full month, combos took a 67.6% share of Kalshi’s volume. Most of those bets were long shots priced below 1 cent. 

This detail adds a very important nuance when interpreting the trading volume number. Kalshi records each contract at its full $1 payout value, regardless of how much the trader paid. Therefore, a parlay bought for less than a cent can still add a dollar to the total. This is where the simultaneous record in trader count growth becomes important because it provides a second perspective on growth actually ramping up. 

Midterm and Bitcoin Markets Added to the October Total

The upcoming U.S. midterm elections on November 3 also caused an influx of capital entering political markets. Midterm markets passed $1.4 billion in volume, and Kalshi alone accounted for nearly $1.1 billion of it. As of Oct. 31, Kalshi’s House control market had traded about $170 million, while its Senate market sat near $111 million.

Crypto-based contracts grew as well. Crypto volume on Kalshi and Polymarket crossed $3 billion for the first time in October and it did so two weeks in a row. Kalshi’s 15-minute Bitcoin up/down contract was the standout, letting traders bet on whether BTC finishes higher or lower inside a quarter of an hour.

Polymarket’s US Arm Hit its Own Monthly High

Polymarket’s regulated U.S. platform set a new monthly high of nearly $10 billion in October, about 15% above its previous record. Combos grew to more than 20% of its volume within days of their wider rollout, which suggests Polymarket is now running the same parlay-heavy playbook that carried Kalshi through football season.

Money also flowed into global events on the platform, including markets on Brazil’s presidential election and the Federal Reserve’s October rate decision. Midterm contracts settle after Tuesday’s vote, while the football markets that drove most of October’s volume still have the rest of the regular season ahead.