Bollinger Bands are like a rubber band around an asset’s price, showing where it’s likely to bounce or break out. They consist of a middle line (a moving average) and two outer bands that measure volatility. How is it used?
- Overbought/oversold: Prices touching or exceeding the upper band may be overbought; touching the lower band may be oversold.
- Volatility squeeze: When bands contract (low volatility), a breakout is likely. Wide bands indicate high volatility.
- Mean reversion: Prices often return to the SMA after touching the bands.
- Middle band: A Simple Moving Average (SMA), typically over 20 periods.
- Upper band: SMA + (k × standard deviation of price over the same period).
- Lower band: SMA - (k × standard deviation).
The standard settings are a 20-period SMA and k = 2 (2 standard deviations).