Bollinger Bands

Bollinger Bands is one of the most widely recognized volatility indicators in technical analysis, developed by John Bollinger in the 1980s. The indicator consists of three lines plotted directly on the price chart: a middle band, which is a simple moving average (typically 20 periods), and an upper and lower band placed a specified number of standard deviations — usually two — above and below the middle band. Because the bands are derived from standard deviation, they automatically widen during volatile market conditions and contract during calmer periods, making them a self-adjusting volatility envelope.

The core trading logic of Bollinger Bands is based on the statistical principle that price tends to stay within the bands the vast majority of the time. When price touches or closes at the upper band, it is considered statistically stretched to the upside, generating a potential sell signal. When price reaches the lower band, it signals potential oversold conditions and a buy opportunity. A "Bollinger Squeeze" — when the bands contract to an unusually narrow range — is a powerful pattern that often precedes explosive breakout moves, as low volatility historically gives way to high volatility. Conversely, very wide bands can signal that a volatile move is nearing exhaustion.

For cryptocurrency traders using automated bots, Bollinger Bands are a foundational tool because crypto markets exhibit extreme volatility cycles that the bands capture naturally. Bots can be configured to sell when price reaches the upper band and buy when it hits the lower band for mean-reversion strategies, or to enter long on a confirmed close above the upper band after a squeeze for breakout strategies. The adaptability of the indicator to changing market conditions makes it suitable for the full range of cryptocurrency market environments, from stable accumulation phases to parabolic trend runs.