Kalshi Outpaces Polymarket as World Cup Cements Prediction-Market Duopoly

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 event contracts tied to outcomes ranging from elections to sporting contests, putting platforms such as Polymarket and Kalshi in increasingly direct competition with traditional bookmakers. The 2026 World Cup has provided a major test of that model, concentrating global attention and trading demand while raising the stakes for licensed US betting operators and regulators overseeing the boundaries between derivatives and gambling.

Prediction-market activity during the 2026 World Cup reached the equivalent of 27% of total legal US sports betting volume, according to the latest data from H2 Gambling Capital. That was three times the 9% share recorded at the start of 2026, with the increase occurring within a month. The figures point to a rapid shift in wagering behavior, though the reports did not disclose an exact dollar value for the trading volume.

Kalshi and Polymarket are prediction markets where contract prices reflect the probability of events. Research focused on the 2026 World Cup found that the composition of each platform's user base influences capital flows. When traders are constrained by nationality and access rules, market prices may reflect systematic national preferences rather than a global consensus.

The latest study compared U.S.-only Kalshi with globally accessible Polymarket. It found that Kalshi users allocated five to six times more money than justified to bets on the U.S. and Mexico teams, while the relevant contracts persistently traded at premiums of up to 40%. The findings indicate that cross-platform arbitrage is insufficient to eliminate the bias.

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.

The 2026 World Cup entered the group stage in June with an expanded field of 48 teams, making qualification paths and scheduling more complex. Prediction markets including Kalshi and yoyo market allow traders to put real money behind contracts on the tournament winner. Real-time prices respond to injuries, squad changes and match results, offering a key gauge of the market’s collective judgment.

Since the 2026 group stage kicked off, France has overtaken Spain on both Kalshi and yoyo market to become the favorite. Contracts trade in dollars or equivalent funds, depending on the platform, and each correct Kalshi contract pays out a maximum of $1. Prices continue to fluctuate with teams’ qualification prospects and the performances of key players.

The 2026 FIFA World Cup is jointly hosted by the United States, Canada and Mexico and has expanded to 48 teams for the first time. Blockchain-based prediction market Polymarket allows users to trade on the probability of match outcomes. Its trading activity reflects the market's collective expectations and underscores the accelerating adoption of Web3 applications at major sporting events.

The World Cup formally kicked off on June 11, 2026, with host nation Mexico facing South Africa in the opening match. Cumulative trading volume for the game on Polymarket quickly exceeded $11 million, while live market odds put Mexico's probability of victory above 70%. Large amounts of onchain capital were concentrated on bets backing the host nation early in the match.

Polymarket and Kalshi are prediction-market platforms that let users trade contracts based on the outcomes of political, economic and other events. Their cumulative trading volume has surpassed $150 billion, underscoring the sector's emergence as a major fintech segment. Kalshi has taken the lead in the U.S. market with authorization from the Commodity Futures Trading Commission.

Polymarket and Kalshi recorded a combined $21.9 billion in monthly trading volume in April 2026, an all-time high. However, Polymarket's monthly volume fell for the first time since August 2025, allowing Kalshi to overtake it in scale. Polymarket has also partnered with Chainalysis to strengthen compliance as it continues seeking to reopen trading to U.S. users.