volatilityintermediate

Bollinger Bands

BB

Bollinger Bands consist of a middle band (20 SMA) with upper and lower bands set at 2 standard deviations above and below. The bands widen during volatile periods and contract during quiet periods, providing a relative definition of high and low prices.

Interactive Chart

117.58

Parameters

Number of periods for the middle band SMA.

Number of standard deviations for band width.

Quick Answer

Price envelope showing volatility around a moving average. ![Bollinger Bands on price chart](https://images.unsplash.com/photo-1535320903710-d993d3d77d29?w=800 "Bollinger Bands showing price volatility") Created by John Bollinger in the 1980s, Bollinger Bands are a volatility indicator. About 95% of price action typically occurs within the bands.

Trading Signals

Squeeze

Neutral

Bands contract significantly, signaling upcoming volatility

Band Width < 20-day low

Upper Band Touch

Neutral

Price touches or exceeds upper band

Price >= Upper Band

Lower Band Touch

Neutral

Price touches or exceeds lower band

Price <= Lower Band

Mean Reversion

Neutral

Price returns to middle band from extremes

Price crosses Middle Band

What are Bollinger Bands?

Bollinger Bands on price chart
Bollinger Bands showing price volatility

Created by John Bollinger in the 1980s, Bollinger Bands are a volatility indicator. About 95% of price action typically occurs within the bands. The bands adapt to market conditions, widening during high volatility and contracting during low volatility.

How to Read Bollinger Bands

Warning

Price touching the upper band doesn't automatically mean sell, nor does touching the lower band mean buy.

Instead, look for: 1) Squeeze patterns (contracting bands) signaling upcoming volatility, 2) Band walks where price hugs a band during trends, 3) W-bottoms and M-tops for reversals.

Trading Signals

Key signals include:

Note

- The Squeeze (low volatility preceding breakoutbreakout Walks (trending markets) - Double bottoms/tops forming at bands - Mean Reversion trades when price returns to the middle band

Trading Strategies

In ranging markets, buy at lower band and sell at upper band. In trending markets, look for pullbacks to the middle band as entry points.

Pro Tip

The squeeze strategy involves waiting for bands to contract, then trading the breakoubreakoution.

Formula

Formula
Middle Band = 20 SMA
Upper Band = Middle + (2 × 20-period StdDev)
Lower Band = Middle - (2 × 20-period StdDev)

Tips & Common Mistakes

Pro Tips

  • Squeeze setups often precede significant moves
  • Use %B indicator for precise band position
  • Combine with volume for breakout confirmation
  • Don't use bands alone - they show volatility, not direction

Common Mistakes

  • Treating band touches as automatic buy/sell signals
  • Ignoring that bands expand and contract with volatility
  • Not considering the overall trend
  • Using same settings for all timeframes

Best Used With

RSIVolumeMACD