Polymarket's "Soccer" category saw over $2 billion in volume during the first ten days of the World Cup, a 300% increase over the prior ten-day period. At the same time, daily average volume for the category grew from $53 million in the month before kickoff to about $220 million during the tournament so far.
The mechanical driver behind this growth is straightforward: the world’s most popular, most-anticipated, quadrennial tournament, having multiple daily sports matches for an entire month, where each match is a short-dated event market that resolves within 90 minutes.
Polymarket isn't the only prediction market that has enjoyed the fruits of the World Cup, as Kalshi's aggregated open interest (OI) reached a record $1.16 billion last Thursday, the first time the platform’s OI surpassed the billion-dollar mark. This marks a 350% year-to-date increase for Kalshi's OI.
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Interestingly, Polymarket's OI levels have remained relatively flat even during the World Cup, while the OI in Polymarket's U.S. arm, which is also CFTC-regulated like Kalshi, has only increased modestly, failing to even reach its April 2026 highs.
