Kalshi Crushes Polymarket in the Prediction Market Race

Combined non-sports prediction market volume reached $10 billion in the week ending September 13, marking a sixth consecutive record, with Kalshi accounting for $9.6 billion and Polymarket reduced to $344.2 million, according to data from Artemis.

How Retail Distribution Tilted the Market

Three months ago, Kalshi and Polymarket were splitting non-sports volume roughly 50/50. A year before that, Polymarket led the category outright, and the reversal traces to brokerage distribution. Kalshi contracts now trade on Robinhood, Coinbase, Webull, and Moomoo, placing event contracts alongside stocks and options inside accounts that millions of retail traders already fund. Roughly one-third of Kalshi's daily flow arrives through Robinhood alone, and Polymarket lacks an equivalent retail gateway. Its Commodity Futures Trading Commission (CFTC)-regulated United States venue, acquired in July 2025 for $112 million when it bought licensed exchange and clearinghouse QCEX, uses different settlement methods from its original on-chain platform. That regulatory compliance earned market access but has not yet translated into the mainstream distribution that Kalshi secured through broker integrations.

Hourly Contracts and the Volume Engine

Product design is amplifying the distribution advantage. Kalshi offers hourly contracts on the S&P 500, Nasdaq, Bitcoin, and Ethereum, instruments that generate high turnover by their nature because each contract expires and is replaced within 60 minutes. Longer-dated contracts, such as those settling on Federal Reserve interest-rate decisions in late October and December, add a layer of volume that persists across weeks. The combination produces a trading cadence closer to a futures exchange than a traditional prediction market.The broader market trajectory underscores the scale shift. Combined monthly prediction market volume across all venues surged from less than $5 billion in September 2025 to approximately $24 billion by April 2026, a nearly fivefold increase in seven months, according to CoinLaw data. When sports volume is stripped from Kalshi's book, non-sports activity still totalled approximately $5.2 billion over the trailing year as of February 2026, an estimate based on CoinLaw's calculation.

Regulatory Standing Remains the Swing Factor

The CFTC claims exclusive jurisdiction over event-contract derivatives in the United States, and Kalshi and Polymarket's US venue both operate under its oversight. Kalshi, which held a CFTC licence before Polymarket obtained one, used that head start to negotiate the brokerage integrations that now drive its volume dominance.Whether Polymarket can close the gap depends on securing similar distribution partnerships or building enough direct user traffic to offset the retail disadvantage. The next volume test arrives around the Nov. 3 midterms, bracketed by Fed decisions on Oct. 28 and Dec. 9.If Polymarket cannot narrow the distribution gap by then, Kalshi's 96% share may harden into a structural lead rather than a cyclical spike. For now, the data suggests that regulatory approval alone does not win prediction markets; placing contracts inside the brokerage apps where retail traders already live does.