Kalshi and Polymarket post strongest months yet with nearly $10 billion in combined November volume

Centralized and onchain prediction markets closed November with their strongest month on record, as Kalshi and Polymarket each set new all-time highs for trading volumes amid surging retail interest, expanding integrations, and a steady drumbeat of headline-driven macro events.

Prediction markets let users buy and sell contracts tied to real-world events, with the price of each contract reflecting the market’s implied odds of that outcome happening. If the event occurs, the contract pays out; if not, it expires worthless. Traders use these markets to gauge sentiment on everything from elections to economic data in real time.

According to The Block’s data dashboard, Kalshi’s monthly spot volume climbed from $4.4 billion in October to $5.8 billion in November, a 32% month-over-month increase and the platform's largest absolute monthly gain to date.

Polymarket also posted its biggest month ever. The New York–based platform saw monthly trading volume rise from $3.02 billion in October to more than $3.7 billion in November, a 23.8% month-over-month jump, extending a run of record-setting activity that began in the summer.

The volume surge continues a breakout year for both platforms, which have increasingly dominated global prediction market flows.

Market share data from The Block shows that the two now control the overwhelming majority of monthly activity in the sector as their product sets, liquidity funnels, and media integrations deepen.

A duopoly ascendant

November’s record highs extend the trend highlighted in The Block's recent reporting on Kalshi and Polymarket’s emerging duopoly. The sector’s capital formation has also kept pace with its trading growth.

Last month, Kalshi doubled its valuation in a matter of weeks, driven by a broad investor bet on the platform's regulated U.S. footprint. The rally followed $1 billion in fresh funding, which pushed Kalshi's market valuation to $11 billion. Across the table, Polymarket has also expanded aggressively following a pivotal regulatory reversal. Following the CFTC’s regulatory nod in mid-November, the company is poised to resume its U.S. operations.

Since then, Polymarket has layered on new distribution partnerships — including Yahoo Finance’s exclusive integration of its prediction market, a multi-year deal with UFC, and widening media embeds via Google Finance, which recently began rolling out Polymarket and Kalshi data directly into search results.

Galaxy Digital has also explored potential liquidity-provision partnerships with both platforms, according to reporting from Bloomberg. The developments underscore a growing institutionalization of a category that started as a niche retail curiosity.