Kalshi surpasses Polymarket in prediction market volume amid a surge in trading in the United States.

Kalshi is leading the prediction market race, accounting for 62% of the total on-chain volume from September 11 to 17, equivalent to over 500 million USD, according to Dune Analytics. Meanwhile, Polymarket holds 37% with approximately 430 million USD. The average open interest of Kalshi reaches 189 million USD, higher than Polymarket at 164 million USD, reflecting a faster trading pace.

Polymarket tends to favor long-term markets, usually lasting several weeks or months, which locks up users' capital for a longer period. The open interest/volume ratio of Polymarket is 0.38, while Kalshi is lower at 0.29, indicating that Kalshi attracts users to trade more frequently, while Polymarket maintains a long-term position.

Although it is lacking in volume, Polymarket is expanding in the US after acquiring the derivatives exchange QCX and partnering with Stocktwits to launch a profit-based market, helping investors hedge risks and monitor market sentiment.