Kalshi and Polymarket US Top Monthly Volume Records Before Month-End

Kalshi and Polymarket US had surpassed their previous monthly trading-volume records in October month-to-date figures before the Nov. 3 midterms, though the totals do not isolate election activity.

Kalshi’s October month-to-date volume was about $65 billion, roughly 10% above its September record. Polymarket US reached about $10 billion, about 15% above its September total, extending its run after a September contract-volume record.

The figures measure notional volume, which counts contracts at face value rather than the cash traders paid. They track trading activity, but do not represent traders’ cash outlay. Because the figures cover month-to-date trading, they are not final October totals.

Kalshi and QCX LLC, doing business as Polymarket US, are designated contract markets listed by the Commodity Futures Trading Commission. The October totals do not separate election contracts from other markets, so they do not establish how much of the increase came from midterm-related activity.

Trading after Nov. 3 will provide a comparison for whether activity continued beyond the election period.