A period of trading activity that precedes the start of the formal trading session. The before-the-bell or pre-market trading session usually takes place in early morning, i.e. between 7:00 a.m. -9:00 a.m. or 8:00 a.m.- 9:30 a.m. each trading day. Investors often keep an eye on pre-market trading activity, considering it a leading precursor for regular hours trading, especially in terms of the volume and trend of the market before formal trading opens. Nevertheless, the types of orders offered by retail brokers may be limited in pre-market trading. Furthermore, trading activity is mediocre in comparison with that of normal hours trading with respect to volume and liquidity. However, investors may use the data to judge the strength of buying in a particular security at the time of regular market open. The information gathered about the pre-market activity can also serve as an indicator of the opening price of the security and how long that price will generally be supported by the market

Pre-market (before-hours trading– BHT) is a part of extended-hours trading (EHT) that also includes post-market or after-hours trading: buying and selling that takes place after the close of a regular trading day.