What Happens If a U.S. Stock Plunges in Premarket Trading After You Set a Stop-Loss Order? Why Your Stop-Loss May Not Trigger
Even if you have placed a stop-loss order for a U.S. stock, the shares will not necessarily be sold when the price falls below your stop price during premarket or after-hours trading. Standard stop orders may trigger only during regular trading hours, and an order could execute at a price far below the stop price when the regular session opens. As of 2026-10-20, U.S. Securities and Exchange