Point of Focus

• Polymarket and Kalshi hit a record $50.6 billion in combined July trading volume.
• Kalshi dominated with $37.7 billion, accounting for nearly 75% of total activity.
• The World Cup helped drive record turnover.

Prediction-market trading reached an all-time high in July as Polymarket, Polymarket US and Kalshi generated a combined $50.6 billion in monthly volume.

Activity increased by 7.8% from the revised June total of $46.95 billion, supported by strong growth at Kalshi and Polymarket’s regulated US platform.

Major sporting events, particularly the FIFA World Cup, appear to have contributed significantly to the record. However, falling open interest toward the end of July suggests that activity cooled after the tournament concluded.

Kalshi dominates with $37.7B in volume

Kalshi remained the largest prediction-market venue by a significant margin, recording $37.7 billion in July volume.

The figure represented an increase of approximately 14% from June and accounted for 74.5% of the combined total across the three platforms.

🚨 MARKETS: #Kalshi and #Polymarket's combined trading volume hit an all-time high of $50.6B in July.

The World Cup fueled the surge – but states are still fighting to shut prediction markets down. pic.twitter.com/lTD904sFIi

— CoinMarginalX (@CoinMarginalX) August 3, 2026

The latest data also revise earlier estimates for June. An initial report placed combined volume at $44.8 billion, including $31.5 billion from Kalshi. The updated dashboard now shows a higher baseline of $46.95 billion as additional trading information became available.

Polymarket US surges as international volume falls

Polymarket US recorded the strongest monthly growth, with trading volume rising 54% to $5 billion. Its international counterpart moved in the opposite direction, falling 26% to $7.9 billion.

Combined activity across Polymarket’s two businesses therefore declined from around $14 billion in June to $12.9 billion in July. Growth in the US was insufficient to offset weaker offshore trading.

Polymarket US expanded access to eligible American users after removing its app waitlist in May. The Commodity Futures Trading Commission lists both Polymarket US operator QCX and Kalshi as designated contract markets.

World Cup drives prediction-market trading

The FIFA World Cup, held between June 11 and July 19, provided platforms with a steady stream of high-profile contracts. Kalshi’s market for the final between Spain and Argentina attracted approximately $1.89 billion in volume.

Chainalysis estimated that World Cup-related blockchain prediction markets generated $20 billion between January and the tournament’s conclusion. Roughly 400,000 wallets traded $5.7 billion during the five-week competition, with World Cup contracts representing about 63% of prediction-market activity over that period.

This Month in Prediction Markets: July has been wild.

> Monthly volume hit an ATH above $52B. Up 2x since January.
> Prediction markets now 27% of all legal U.S. sports betting. Was 9% in January.
> $20B+ traded on the World Cup alone.
> Robinhood Q2: prediction markets outearn… pic.twitter.com/AU1y3XFALO

— Outcome (@Outcomexyz) August 1, 2026

Those figures are not directly comparable with the broader July total because Chainalysis focused on blockchain-based markets, while the $50.6 billion figure includes Kalshi’s centralized activity.

Open interest across the three venues declined from roughly $2 billion at the beginning of July to $1.2 billion by month-end. The drop indicates that many positions closed or settled following the World Cup, leaving questions over whether record trading levels can be sustained in August.