Volatility Range can help you interpret volatility, making it easier to select the most compatible option for your strategy. You can choose between various measures of historical and implied volatility to analyze. Displaying the percentage bands allows you to see more easily identify when volatility readings are above or below the user defined limits.
A common use for applying volatility to an option strategy is to compare an option's volatility to its historical range. When current readings of volatility are considered high the option premium is considered to be expensive. When current readings of volatility are considered low the options premium is considered inexpensive. By default the upper and lower percentage bands are set at 80 percent to define a high level of volatility and 20 percent to define a low level of volatility. An option trader would seek out strategies that allow for the sale of an option when premiums are high, while following long strategies when premiums are low.