World Cup boom on Polymarket left most traders with tiny gains

Prediction markets pulled in sports-scale trading during the World Cup, but the payoff on Polymarket was heavily concentrated. Data cited in the source shows Polymarket and Kalshi handled about $5.57 billion in combined volume on tournament winner contracts, with roughly $4.28 billion on Polymarket and $1.29 billion on Kalshi.

On Polymarket, broad participation did not translate into broad profits. A Dune Analytics review of 194,422 wallets in the World Cup winner market found that 66.7% ended with losses. More than 114,000 wallets lost less than $100 each, with average losses of $9.34. On the winning side, nearly 58,000 profitable wallets made an average of just $4.85.

The largest returns went to a very small group. Just 54 wallets made more than $100,000 each, collecting $22.3 million in total, almost 60% of all positive returns in the analysis. Five accounts made more than $1 million each. Losses were concentrated too: 43 wallets lost over $100,000 apiece, for a combined $15.19 million, about 40% of all losses.

The tournament also pushed prediction markets deeper into mainstream sports betting. H2 Gambling Capital estimated they accounted for about 27% of legal US sports-betting volume during the World Cup, up from about 9% at the start of the year.