JPMorgan memo warns 320,000 bankers to be cautious on Kalshi and Polymarket

JPMorgan circulated an internal red-flag memo on May 20, 2026, warning its roughly 320,000 employees to be cautious when trading on prediction market platforms Kalshi and Polymarket. The notice specifically flags insider trading risks as event contracts expand into categories touching publicly traded companies and macroeconomic data. The memo singles out both platforms by name and reflects deepening institutional scrutiny of bank staff activity on event-contract venues. The warning follows a separate JPMorgan policy shift just ten days earlier that let employees trade prediction markets without pre-clearance, pairing new freedom with explicit caution. Mainstream financial infrastructure interest in the sector is growing: Robinhood now offers direct Kalshi event contract access to retail customers, and Intercontinental Exchange is active in the space.