One of the momentum indicators used in technical analysis of stocks is Bollinger Band. Bollinger Band (BB) helps to ascertain the volatility with the support of standard deviation. Herein, the upper band defines the higher range that a stock can deviate from the mean and vice versa. Besides ascertaining the price range and volatility, Bollinger Band also reflects the breakout in the form of “Expansion” and “Contraction” formation.
Expansion of Bollinger Band indicates a wide opening of the bands in the opposite direction with price rigorously following a strong trend. This scenario occurs normally after a sideways movement or consolidation.