The Nasdaq-100 Pre-Market Indicator is calculated based on the last sale of Nasdaq-100 securities during the pre-market trading period of 8:15 a.m. to 9:30 a.m. EST. For Nasdaq-100 securities that do not trade in the pre-market, the calculation uses the last sale from the previous day's 4 p.m. closing price. The Nasdaq-100 Pre-Market Indicator and After Hours Indicator are useful gauges of market sentiment during extended trading hours.