Pre Market Trading

Pre-market trading refers to the trading activity that occurs before the regular market session begins. In India, NSE and BSE conduct a pre-open session from 9:00 AM to 9:15 AM IST before the regular trading session opens at 9:15 AM. During the pre-open session, investors can place, modify, or cancel orders — both limit and market orders — and the exchange uses a call auction mechanism to discover the opening price based on the highest volume-matching price across all orders received. The pre-open session is divided into three phases: order collection (9:00 AM to 9:08 AM), order matching (9:08 AM to 9:12 AM), and buffer time (9:12 AM to 9:15 AM). The equilibrium price determined in the pre-open session becomes the opening price for the regular session. The pre-open call auction is particularly important for managing volatility caused by overnight news — allowing price discovery to occur in an orderly manner rather than through a chaotic opening surge or crash.