The growth of electronic communications networks (ECNs) has made extended-hours trading available to even individual retail investors. This gives you the opportunity to place orders during time periods previously reserved for large institutional investors.

The extended session refers to the period either after regular trading hours end, or before they begin. For U.S. markets, it is usually 8:00 am – 9:30 am ET and 4:00 pm – 7:55pm ET.