网站上写的: Pre-market trades can be placed and are eligible for execution between 7:00 a.m. ET and 9:15 a.m. ET. Extended-Hours Trading Trade at your convenience: Place trades online before and after standard daytime market hours. Check the price before you order: Free real-time and depth of book quotes are available during the extended-hours trading sessions. Direct Matching of Orders: Electronic Communications Network (ECN) systems electronically match buyers and sellers, ranked first by price, next by time or order places. Enjoy low commissions: After-hours trades follow your regular commission schedule1. Trading Hours: Pre-market trades can be placed and are eligible for execution between 7:00 a.m. ET and 9:15 a.m. ET. After-hours trades may be placed and eligible for execution between 4 p.m. and 8 p.m. ET, Monday to Friday. There is no trading on market holidays2.