Kalshi trader wins $3.8M on US Open upset

A trader on the Kalshi prediction market platform secured a payout of nearly $4 million after correctly forecasting an upset at the US Open. The user held an $888,234.14 position on Ben Shelton to defeat Carlos Alcaraz, a match where the Spaniard was initially favored with a 75% win probability.

Kalshi, a federally regulated financial exchange overseen by the Commodity Futures Trading Commission (CFTC), is seeing increased activity surrounding the start of the NFL season. The platform offers markets on various real-world outcomes, including sports, politics, and finance. New user promotions are currently available for those trading on upcoming NFL matchups, such as the season opener between the New England Patriots and the Seattle Seahawks.

Kalshi remains legally accessible to residents in many U.S. states, including Pennsylvania, and operates as a regulated exchange rather than a traditional sportsbook.