TLDR Sports made up 83% of prediction market open interest in October, up from 73% in September. Daily turnover rose 55% to an all-time high of $4.13 billion, per Jefferies. Open interest climbed 45% to a record $3.27 billion. Weekend combo bets leaned toward NFL and college football, helping DraftKings’ DKeX. Polymarket and Rothera posted monthly gains as non-sports volume also rose 55%.
Sports contracts tightened their grip on prediction market money in October. Sports made up 83% of open interest last month, up from 73% in September, according to a client report from Jefferies analyst Daniel Fannon.
Open interest is the total value of contracts that traders still hold. It rose 45% from September to a record $3.27 billion.
Trading activity also reached a new high. Daily turnover on yes/no exchanges climbed 55% in October to an all-time high of $4.13 billion, Fannon said.
Prediction markets traded $23.4B in 30 days. Up 21% while crypto bled.
@Kalshi $16.4B, +20%, 70% of all volume
@Polymarket $5.8B, +23%
@predictdotfun $408M, +34%
@HyperliquidX outcomes $80M, x2.1
@xomarket $73M, x3
Only @opinionlabsxyz shrank, -19%
Same 30 days,… pic.twitter.com/kFklHlHqO0
— t0mj (@tomjke) November 4, 2026
Football and Basketball Drive Sports Volume
Sports event contracts averaged $2.978 billion in daily volume in October. That figure was up 55% from the month before.
The start of the 2026-27 NBA season helped lift activity. So did the busy stretch of the college football and NFL seasons.
Even with that growth, sports held a 78% share of average daily volume. That share was flat compared with September, because non-sports volume grew at the same pace.
Fannon also tracked how traders use combos, the prediction market term for parlays. Combo use rises on weekends, which suggests traders mostly use these multi-leg bets