Kalshi Prediction Market Hits Record $4.39B Monthly Volume in October, Outpacing Polymarket

Kalshi, a US-based prediction market and main competitor to Polymarket, achieved a record monthly trading volume of $4.39 billion in October 2025, driven by expansion in sports markets and institutional interest. This surge contributed to the overall prediction market sector exceeding $1 billion in monthly volumes, with Kalshi's strongest week at the end of October seeing nearly $1 billion in notional volumes alone.

In contrast, Polymarket, a crypto-native platform, recorded $2.29 billion in cumulative volumes for October, marking its most successful month since October 2024 when volumes first surpassed $2 billion. Polymarket relied on smaller bets and saw active wallets expand to over 76,000 by October 31, breaking previous records from the 2024 US Presidential Elections. However, both platforms faced operational glitches, including market outages, and skepticism over their risk approaches being perceived as gambling.

Kalshi's growth is attributed to its Web2-focused strategy, including integrations with Robinhood and Webull, which broadened mainstream adoption without requiring blockchain or crypto ownership. The platform secured a $5 billion valuation after a $300 million Series D funding round, as noted by co-founder and CEO Tarek Mansour: "Our vision is to redefine risk management for everyone, enabling millions to hedge and speculate on real world events." Meanwhile, Polymarket's on-chain model continues to attract crypto-native users, with heightened activity in current events like the New York mayoral election, where Polymarket reported $365 million in trades compared to Kalshi's $71 billion.

Despite the growth, both platforms face regulatory uncertainties and potential competition from rising alternatives. As crypto trading slows, prediction markets are emerging as a key alternative, influencing DeFi protocols and risk management strategies.