World Cup Ignites Prediction Markets: Polymarket Trading Volume Surges 300%, Kalshi Open Interest Hits Record $1.16 Billion

Odaily Planet Daily News In the ten days leading up to the World Cup, Polymarket's football category trading volume exceeded $2 billion, a 300% increase from the previous ten days. Average daily trading volume rose from $53 million before the tournament to approximately $220 million. Meanwhile, Kalshi's open interest reached a record $1.16 billion last Thursday, surpassing the $1 billion mark for the first time, representing a 350% increase since the beginning of the year.

Although Polymarket's open interest levels remained relatively stable during the World Cup, and the open interest of its U.S. branch saw only modest growth, it has not yet reached the highs seen in April 2026. Kalshi's open interest is growing faster than its trading volume, indicating that its user base holds positions for longer periods and that larger directional positions are emerging. Its CFTC-regulated channels and direct fiat on-ramps are attracting U.S. institutional and high-net-worth dollar investors. (The Block)