World Cup Ignites Prediction Markets: Polymarket Trading Volume Surges 300%, Kalshi Open Interest Hits Record $11.6 Billion

According to Odaily, within the first ten days of the World Cup, Polymarket's football category trading volume exceeded $2 billion, a 300% increase compared to the previous ten days. The average daily trading volume rose from $53 million before the tournament to approximately $220 million. Meanwhile, Kalshi's open interest reached a record $11.6 billion last Thursday, breaking the $1 billion mark for the first time, representing a 350% increase since the beginning of the year.

Although Polymarket's open interest remained relatively stable during the World Cup, and its US-based branch saw only modest growth, it has not yet reached the highs seen in April 2026. Kalshi's open interest has grown faster than its trading volume, indicating longer holding periods among its user base and the emergence of larger directional positions. Its CFTC-regulated channel and direct USD deposit options have attracted US institutions and high-net-worth dollar investors. (The Block)