Prediction markets allow people to buy and sell contracts tied to the outcome of future events, instead of acquiring traditional financial assets. Traders can speculate on everything from elections and economic data to sporting championships, with prices changing as expectations shift.
The FIFA World Cup, one of the world's largest sporting events, created ideal conditions for active trading, as each match opened up new opportunities.
Trading Activity Reaches New Heights
The figures recorded in June and July on the Dune.com prediction market dashboard clearly illustrate how sharp this growth has been. The total notional volume of the prediction market reached $54.09 billion in July compared to $49.95 billion in June, representing a growth of approximately 8.3% in one month.
Kalshi dominated the market, processing $38.65 billion, or roughly 71.5% of the total volume. Polymarket generated $7.89 billion, and Polymarket (US) added another $4.86 billion, bringing the combined volume of the Polymarket ecosystem to nearly $12.75 billion, or about 24% of the monthly volume. The remaining share was taken by Opinion, predict.fun, Crypto.com, Limitless, and smaller platforms, highlighting how concentrated the industry has become around Polymarket and Kalshi.
Platform Revenues
Increased trading activity naturally led to higher platform revenues. According to Dune.com, estimated fees for prediction markets in July grew to approximately $327.67 million.
Kalshi again led the industry, earning roughly $252.92 million, or about 77% of all estimated fees. Polymarket earned $39.72 million, and Polymarket (US) earned $29.52 million. Predict added $4.44 million, Limitless just over $1 million, and Opinion about $50,000. The distribution of fees largely mirrored trading activity, reaffirming Kalshi's dominant position.
Increase in User Participation
The growing interest was equally evident in transaction count. In July, platforms processed nearly 365.92 million transactions as traders constantly adjusted their positions throughout the tournament.
Kalshi accounted for 246.73 million transactions, representing approximately 67.4% of the total activity. Polymarket recorded 62.03 million, and Polymarket (US) recorded 38.13 million. Combined, the two Polymarket platforms accounted for roughly 100 million transactions, or about 27% of all market activity. Predict.fun accounted for another 16.74 million, while the remaining platforms processed relatively small volumes.
Growth in Capital Deployed
The World Cup also prompted traders to hold more funds in open positions. Open interest, which measures the total value of active contracts yet to be settled, approached $1.91 billion at the beginning of July.
Kalshi accounted for approximately $1.30 billion, representing about 68% of the total open interest. Polymarket accounted for $419.21 million, and Polymarket (US) for another $154.30 million. Predict.fun accounted for $23.76 million, while Opinion, Limitless, and other platforms held only a small share of open interest.
Why Sports Matter
Unlike financial markets, prediction markets thrive on uncertainty and a constant influx of information. Every goal, injury, referee decision, and unexpected turn in a tournament instantly changes the perceived probability of future outcomes, prompting traders to adjust their positions throughout the competition. The World Cup's nearly month-long schedule created a continuous stream of tradeable events, sustaining high activity from the opening match to the final.
The tournament also broadened participation beyond traditional prediction market users. Sports fans who might never trade contracts tied to inflation or elections suddenly had the opportunity to follow familiar events, enhancing liquidity and bringing additional capital into the ecosystem.
What Comes Next
The FIFA World Cup demonstrated that global sporting events can dramatically expand participation in prediction markets far beyond election betting and other themes, driving growth across virtually all industry metrics. Whether these elevated levels will persist after the tournament concludes has become one of the sector's key questions.
Investors and platform operators will now watch upcoming sports calendars, major political events, and regulatory changes to determine whether prediction markets can retain their expanded user base or if activity will gradually return to pre-tournament levels. With the end of the FIFA World Cup, open interest in prediction markets has significantly declined.
