Polymarket's US return reignites rivalry with Kalshi for retail prediction-market traders

• —Polymarket operated outside the US for years after a 2022 CFTC settlement that included a fine and a US user block
• —Kalshi secured CFTC approval and won court battles over election contracts while its rival was absent
• —Competition will center on event catalog, fees and funding options — traditional dollars or stablecoins
• —State regulators question whether sports contracts resemble traditional betting