Polymarket Trading Volume by Week or Category

Polymarket uses taker notional volume, which multiplies the number of contracts traded by the price paid at the time of the trade. This differs from Kalshi’s methodology, which multiplies contracts by their $1 face value regardless of price paid.

No. Kalshi counts volume by multiplying contracts by their $1 face value. Polymarket uses taker notional volume, which multiplies contracts traded by the price paid at the time of the trade. The two figures are measuring related but structurally different things, which means direct comparisons require caution.

We try to update all charts update daily. Weekly figures are finalized each Sunday and locked; bars showing the current week reflect volume to date, not a completed week. Monthly figures follow the same daily cycle.

No. The chart uses Polymarket’s international volume. Polymarket US, the CFTC-regulated product, is a separate platform and represents a small fraction of Polymarket’s total activity.

It carries more uncertainty than Kalshi’s. Beyond the methodology issue above, a Columbia University study estimated that roughly 25% of Polymarket’s historical volume reflected wash trading, with the figure running higher in sports markets specifically. Kalshi has a different risk profile on this front.

The change is significant for volume interpretation because the prior zero-fee environment is widely cited as a condition that made wash trading cheap and common on the platform. Whether fees reduce artificial volume meaningfully will become clearer over the coming months.

Not cleanly. The two platforms use different volume methodologies, operate under different regulatory frameworks, and serve partially different user bases. The market share figures on this page use each platform’s reported numbers on a consistent weekly basis, which is the most comparable view available, but the figures should be treated as directional rather than precise.