The Bollinger BandWidth is the numerical difference between the value of the upper Bollinger Band and the lower Bollinger Band. As volatility increases and the Bollinger Bands get wider, the BandWidth indicator value will increase. As volatility decreases and the Bollinger Bands get closer, the BandWidth indicator value will decrease. The BandWidth indicator helps show volatility as it increases and decreases.

Typical use is to find times of low volatility that start to breakout as the price moves to one Bollinger Band. If volatility continues to increase and the price stays on one band, it can signal a trend as the Bollinger Bands get wider.

You can change the inputs to match the Bollinger Bands indicator that comes with your metaTrader installation. The inputs include:

• BandPeriods: The number of periods used to calculate the moving average in the middle of the Bollinger Bands
• Deviations: The number of standard deviations used to calculate the upper and lower Bollinger Bands