Polymarket US has traded $27.4B in 2026 through Oct. 15, with September its busiest month at $8.8B
DeFi Rate's venue tracker puts Polymarket US October volume so far at $5.7B for an 11.1% share, with its share in the week of Oct. 12 at 10.8% on $1.15B — a venue-volume…
September leads Polymarket US activity
Polymarket US has recorded $27.4B in trading volume in 2026 through Oct. 15, according to DeFi Rate’s venue tracker. September remains its busiest month, accounting for $8.8B of that total.
October volume so far stands at $5.7B, giving the venue an 11.1% share, according to DeFi Rate. For the week of Oct. 12, the tracker reports $1.15B in volume and a 10.8% share.
The tracker’s rolling-period figures show $11.6B in contracts traded over Sep 15-Oct 14, 2026. That represented 12% of prediction-market volume and an increase of 139% from the preceding 30 days.
DeFi Rate separately reports $3.3B in dollars paid for Sep 15-Oct 14, 2026. That measure is distinct from the $11.6B contract-volume figure, making the choice of metric important when comparing activity.
What it means for prediction markets
- The reporting window matters: The 10.8% weekly share, 11.1% October share and 12% rolling-period share describe different intervals, not directly comparable snapshots.
- Growth and market share measure different things: The 139% increase captures growth in Polymarket US contract volume against the preceding 30 days; the 12% figure measures its share of prediction-market volume.
- Volume is not an outcome forecast: These venue-level totals describe trading activity, rather than probabilities for individual contracts.
- Defirate (defirate.com)https://defirate.com/prediction-markets/volume/polymarket-us/