World Cup Drives Prediction Markets to 27% of US Sports Betting

Prediction markets let traders wager on real-world outcomes, making the 2026 FIFA World Cup a major test of the sector’s ability to attract mainstream users. Kalshi and Polymarket now account for more than 95% of the market, cementing a duopoly in which scale, consumer reach and marketing spending increasingly determine which platform converts attention into trading activity.

After the tournament concluded in July 2026, Kalshi reported $54.338 billion in total platform trading volume, 2.6 times Polymarket’s tally. Kalshi also led in app downloads and aggregate trading value, helped by heavy advertising spending. Polymarket continued to draw more website visits, but that traffic did not translate into a volume lead, leaving Kalshi ahead on the industry’s most closely watched commercial measures.

The 2026 FIFA World Cup, hosted by the United States, Canada and Mexico, also served as a large-scale test of crypto-based prediction markets. Polymarket lets traders buy and sell contracts tied to match outcomes, with prices acting as market-implied probabilities. The tournament’s global reach, heavy betting interest and transparent wallet data made the platform a useful case study in whether crowd forecasts translated into profits — and how evenly those gains were shared.

By the tournament’s conclusion on July 19, 2026, more than $474 million had been wagered before matches on Polymarket. The contracts posted an aggregate hit rate of 62.97% and about $28.88 million in net profit. Returns were sharply concentrated, however: the 10 most profitable accounts captured more than half of total gains, while one wallet earned $8.25 million from just two matches. The figures suggest a small number of large winning positions substantially lifted the market’s average performance.

Prediction markets allow users to trade contracts tied to the outcomes of sporting, political and other events, with prices reflecting the market-implied probability of each result. Betting demand generated by the 2026 FIFA World Cup rapidly expanded Kalshi and Polymarket, bringing greater scrutiny to their liquidity, compliance and regulatory disputes across U.S. states.

Kalshi and Polymarket recorded a combined $44.8 billion in trading volume in June 2026, up 75% from May. Kalshi's monthly volume surged 87.4% to a platform record. Polymarket also returned to growth, supported by World Cup enthusiasm and U.S. market demand, though both companies continued to face regulatory challenges from several U.S. state governments.