What are Bollinger Bands? Volatility Analysis Guide
Bollinger Bands are a popular technical analysis tool developed by John Bollinger in the 1980s and used for volatility measurement. They consist of three bands and visually show 'how wide' a range the price is moving in.
The 3 Components of Bollinger Bands
- Middle Band: N-period SMA (usually 20)
- Upper Band: Middle Band + (K × Standard Deviation). Considered a resistance zone
- Lower Band: Middle Band - (K × Standard Deviation). Considered a support zone
Standard parameters: 20-period SMA, 2 standard deviations (2σ). These settings theoretically keep approximately 95% of the price within the bands.
How are Bollinger Bands Interpreted?
Band Width: Volatility Indicator
If the bands are wide, it means the market is volatile (active). When the bands narrow (squeeze), a period of low volatility is occurring and a big move may be coming soon. This squeeze condition is known as the 'Bollinger Squeeze'.
Bollinger Squeeze: When the bands come together, a large price move may be approaching. The bands do not tell you which direction it will be, so confirm with indicators like MACD or RSI.
Touching the Bands: Buy/Sell Signal
- If price touches/crosses the lower band: Oversold, possible reversal
- If price touches/crosses the upper band: Overbought, possible pullback
- If price goes outside the bands: Strong momentum, trend may continue
Middle Band: Support/Resistance
The middle band (20 SMA) usually acts as dynamic support or resistance. In an uptrend, price stays above the middle band; in a downtrend, it stays below.
Bollinger Band Walking
In strong trends, price can travel along the outside of the upper band for a long time (or the lower band). This situation is known as 'band walking' and indicates that the trend is strong. Interpreting touching the upper band as a sell signal during this period can be misleading.
Parameters: How to Optimize?
| Parameter | Default | Lower | Higher |
|---|---|---|---|
| Period (Window) | 20 | More sensitive bands | Smoother bands |
| Standard Deviation | 2.0 | Narrower bands | Wider bands |
Using Bollinger in Optimo
When Bollinger Bands are selected, Optimo optimizes the window period and the standard deviation coefficient. For crypto markets, 15/1.8 or 25/2.2 may give better results than 20/2.0. You can leave it to Optimo instead of finding these combinations manually.
