Kalshi Outpaces Polymarket in Weekly Prediction Market Activity
Kalshi led the on-chain prediction market from Sept. 11–17, with trading volumes topping $500 million and average open interest of $189 million. Polymarket lagged with $430 million in volume and $164 million in open interest, Dune Analytics data show.
The platforms’ open interest-to-volume ratios highlight trading behavior differences: Kalshi’s 0.29 ratio indicates faster turnover, while Polymarket’s 0.38 ratio reflects longer-term market positions. Polymarket is simultaneously building U.S. operations via QCX acquisition and new earnings-focused markets with Stocktwits.
