The US stock market trading hours are from 9:30 am to 4:00 pm of New York time. But the exchanges also have extended hours before the opening and after the close of the main session. They are called "Pre-Market" and "Post-Market" (sometimes post-market is called "After Hours").
During these periods, you can also buy and sell stocks, but such trading has several important nuances.
Pre-market and post-market hours
It is difficult to say definitively when extra hours begin and end in the US market. There seems to be no unified time - different exchanges have their own:
• The New York Stock Exchange (NYSE) website states that preliminary activity begins at 6:30 or 7:00 am pf New York time. The post market on the NYSE runs from 4:00 pm to 8:00 pm.
• According to NASDAQ rules, the pre-market starts at 4:00 am of New York time. The post-market starts at 4:00 pm and ends at 6:30 pm.
• In addition to the NYSE and NASDAQ, there is a developed network of electronic exchanges (Electronic Communication Network, ECN) in the US. The schedule of pre- and post-trading hours may also differ.
In any case, the most “adequate” activity usually occurs from about 8:00 to 9:30 am in the pre-market and from 4:00 to 5:30 pm in the post-market. Although in the post-market, “normal” trading may last longer, because some Americans find it more convenient to invest in the evening, after education courses or work.
• Also, extended hours may vary depending on your broker company. Some brokers only providepre-market and post-market access for an hour before the market opens and an hour after the market closes, such as Freedom Broker.
Read more about the nuances of trading in the pre-market and post-market in our blog Features of trading in the pre-market and post-market