Polymarket has captured 43.8% of the football trading volume compared to its rival Kalshi. The platform achieved this share within months of launching its US operations in late 2025, challenging a competitor that entered the sports prediction market earlier in 2025.
Over a recent 30-day period, the combined sports trading volume on both platforms reached approximately $9.33 billion. Of this total, Kalshi processed $6.03 billion, while Polymarket accounted for $3.30 billion in trading activity.
During the first week of the 2026 NFL season, from September 7 to 13, Kalshi processed over $983 million in contracts. In the same timeframe, Polymarket recorded approximately $27.6 million in NFL-related trading volume.
Kalshi has focused on integrating with traditional financial infrastructure and offering bundled outcome products. In early September 2026, the platform reached a record single-day trading volume of $2.29 billion, largely driven by sports markets.
Polymarket leverages its international platform's liquidity and momentum gained from the 2026 World Cup. The event served as a catalyst for user adoption among US-based traders, helping the platform establish a presence in the American football betting sector.
