After the market opens, the opening range is a set of highs and lows for a set time period. Typically, this is the first 30 or 60 minutes of trade, and it is one of the most crucial chart patterns for profiting the stock market.
The size of the opening range is the difference between these two prices. We measure the range size by the green lines. The top horizontal line depicts the high opening range, while the lower horizontal line depicts the low opening range.