How Stock Market Trading Sessions Work

Each exchange publishes the hours in which it accepts and matches orders, set in its own time zone. Within the regular session there are usually phases: an opening phase in which orders are collected and an opening price is determined, a continuous phase in which orders are matched as they arrive, and a closing phase that determines the closing price. Borsa Istanbul uses a call method at the open and at the close of its equity market, and the NYSE holds auctions at the open and the close of its core session.

Because exchanges sit in different time zones, their sessions overlap only partly. The Tokyo session ends before London opens, and the New York session overlaps the London afternoon. Exchanges close on public holidays and some end early before holidays, and each exchange publishes its own calendar. Daylight saving time moves the clock hours of some exchanges but not of others, so the time difference between two markets changes during the year.

The closing price is the price set at the end of a regular session and is the reference that most daily data series use. After the regular session many venues allow limited extended trading, covered in the pre-market guide, and prices from that period are normally not part of the official daily close. An instrument that trades around the clock, such as most crypto assets, has no session close in this sense, and a daily candle is cut at a time chosen by the data provider.