Pre-market and after-hours

Pre-market and after-hours are the trading windows before and after the regular session. They exist because much of the news that moves a company, starting with its results, is published outside regular hours. They carry far less volume than the session, so spreads widen and a spectacular move can rest on very few trades. An 8% jump after hours is not a reliable guide to where the stock will open the next day.

See the full glossary · What the Celsmar financial terminal is

Definition for informational purposes. It is not financial advice nor a recommendation to buy or sell.