As a hypothetical example, assume the first value of a five-day ATR is calculated at 1.41, and the sixth day has a true range of 1.09. The sequential ATR value could be estimated by multiplying the previous value of the ATR by the number of days less one and then adding the true range for the current period to the product.
Next, divide the sum by the selected timeframe. For example, the second value of the ATR is estimated to be 1.35, or (1.41 * (5 – 1) + (1.09)) / 5. The formula could then be repeated over the entire period.
While the ATR doesn’t tell us in which direction the breakout will occur, it can be added to the closing price, and the trader can buy whenever the next day’s price trades above that value. This idea is shown below. Trading signals occur relatively infrequently but usually indicate significant breakout points. The logic behind these signals is that whenever a price closes more than an ATR above the most recent close, a change in volatility has occurred.