TL;DR
Kalshi, Polymarket, and Polymarket US generated $50.59 billion in combined trading volume during July, setting a new monthly record and rising 7.8% from June’s $46.95 billion. Prediction markets gained momentum as the FIFA World Cup concentrated attention on high-profile event contracts and pulled enormous sums into a sector still negotiating its legal identity. The record was not simply a broad market expansion, but a World Cup-driven surge distributed unevenly across three platforms throughout the month. The milestone confirms accelerating demand, yet the composition reveals traders were shifting where they participated, not merely increasing activity everywhere.
Kalshi remained the clear leader with $37.7 billion in July volume, representing 14% monthly growth. The two Polymarket venues moved in opposite directions: the main offshore platform contracted 26% to $7.9 billion, while Polymarket US increased 54% to $5 billion. The regulated American platform gained sharply, but Polymarket’s combined footprint still declined from $14 billion to $12.9 billion. That divergence suggests the opening of the US service changed trading routes, redirecting activity toward a locally available venue rather than producing equal growth across the broader Polymarket ecosystem during a month of exceptional headline activity worldwide.
The World Cup supplied the month’s most visible catalyst. Kalshi’s market on the final between Spain and Argentina attracted about $1.9 billion, while Polymarket’s contract predicting the tournament winner drew roughly $4 billion. A small number of globally watched events generated an extraordinary share of attention and turnover. Yet open interest across the three platforms fell from around $2 billion at the beginning of July to $1.2 billion by month-end after the tournament concluded, raising a difficult question about how much of the record reflected durable adoption versus temporary concentration around a singular sporting spectacle.
The US market structure adds another complication. Polymarket US removed its initial waitlist restrictions in May, allowing American users to participate directly on a platform regulated by the Commodity Futures Trading Commission. Earlier estimates suggested US traders had generated about 30% of offshore Polymarket volume during the 12 months ending April 30. Legal scrutiny nevertheless persists, with more than a dozen state regulators accusing both platforms of offering unlicensed gambling contracts. The platforms and the CFTC argue federal oversight preempts state action, leaving record volume alongside a still unresolved jurisdictional battle over sports-related prediction markets.
