After-hours trading

After-hours trading is stock trading that occurs outside the traditional trading hours of the major exchanges, such as the New York Stock Exchange and the Nasdaq Stock Market.

Since 1985 the regular trading hours have been from 9:30 a.m. to 4:00 p.m. Eastern Time.
Trading outside these regular hours is not a new phenomenon, but it has generally been limited to high net-worth investors and institutional investors, such as mutual funds.

The emergence of private trading systems, known as electronic communication networks, or ECNs, has allowed individual investors to participate in after-hours trading.

After Hours trading on a day with a normal session is 4:15 - 8 p.m. EST