The price action was really unusual today. The Nasdaq sold off sharply with a 162 point range in the first 15 minutes. After the first 15 minutes of trade, the entire range for the rest of the day was less than 100 points. Price action in the S&P was similar, where the range of the first 15 minutes was greater the range of the rest of the day.
This is similar to our analysis comparing the day session range to the overnight range.