In the description of the indicator in the book “Bollinger on Bollinger Bands”, it is said that the price remains at the borders of the lines 95% of the time and escapes those borders in 5 remaining percent. If volatility on the market is low, the upper and the lower lines are close to one the other, while the price is trading between them; the higher the volatility, the wider the channel formed by the three lines (pic 1). According to the classification, the Bollinger Bands are a trend indicator as it shows both flats and directed price movements. The timeframe may be anything from M1 to a year.