The Average True Range(ATR) is a technical indicator that measures the volatility of an asset’s price.The average true range is calculated by taking the true range and dividing it by the number of periods in the time series. The true range, in turn, is calculated by taking the difference between the highest high and lowest low for a given period.The ATR can be used to identify overbought and oversold levels, as well as potential reversal points.There are many different ways to calculate ATR, but they all boil down to calculating how much a stock's price has changed with respect to its own history.