Standard US equity markets are open 9:30am to 4:00pm Eastern Time on weekdays. Pre-market sessions extend from 4:00am and after-hours from 4:00pm to 8:00pm, but only a handful of US brokers route orders genuinely 24 hours a day, five days a week ('24/5'). The mechanism is usually an ATS (alternative trading system) such as Blue Ocean ATS — a dark pool that matches buy and sell orders overnight while the lit exchanges are closed.
Liquidity in the overnight window is a fraction of regular-session volume, so bid-ask spreads are wider and a market order can fill far from the last consolidated price. Most brokers that offer 24-hour trading require limit orders only during the overnight session for this reason. Eligibility is also limited to a defined list of tickers — typically the S&P 500 and Nasdaq-100 constituents, plus large-cap ETFs.
Brokers in the buystock.net matrix that offer some form of 24/5 retail trading include Charles Schwab (thinkorswim), Interactive Brokers (IBKR Overnight Trading on the Blue Ocean ATS), Robinhood (24 Hour Market), Firstrade, Webull and Moomoo. The eligibility list and exact session hours differ by broker, and brokers can suspend overnight trading without notice during news events or earnings releases.
Overnight trading is not the same as futures trading. CME equity-index futures (ES, NQ) trade nearly 24/5 and are often used by professionals to hedge or speculate around overnight news, but they require a futures account and have very different contract specifications, margin and tax treatment compared to spot equities.
