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IntermediateTechnical Analysis 12 min read

Bollinger Bands: Volatility & Mean Reversion

How to use Bollinger Bands for volatility measurement, squeeze setups, and mean-reversion trades. Includes crypto-specific strategies.

Bollinger Bands are a volatility indicator consisting of three lines: a middle band (20-period SMA), an upper band (2 standard deviations above), and a lower band (2 standard deviations below). They expand during high volatility and contract during low volatility, creating a dynamic envelope around price.

Created by John Bollinger, the bands contain approximately 95% of price action within them. Touches or breaks of the bands don't automatically signal trades — context matters. The bands are best used for measuring volatility and identifying potential mean-reversion or breakout opportunities.

Bollinger Bands

OverboughtOversoldPriceBandsSMA

Narrow bands = low volatility (squeeze). Wide bands = high volatility (expansion). Price at upper band = overbought, lower = oversold.

The Bollinger Squeeze

When the bands contract to their narrowest width, it signals a squeeze — a period of unusually low volatility that typically precedes a major move. The direction of the breakout from a squeeze determines the trade.

In crypto, Bollinger squeezes on the daily chart often precede 20-50% moves. The longer the squeeze, the more explosive the eventual breakout. Use Bandwidth (upper band - lower band / middle band) to quantify squeeze intensity — lower values = tighter squeeze.

Pro Tip: Don't try to predict squeeze direction. Wait for the breakout candle to close outside the bands with volume confirmation, then enter in that direction with a stop at the opposite band.

Mean Reversion with Bollinger Bands

In ranging markets, price tends to bounce between the upper and lower bands — touching the upper band and reverting to the middle, or touching the lower band and bouncing back. This creates mean-reversion trade opportunities.

The key rule: only trade mean-reversion when the bands are flat or slightly expanding (ranging market). When bands are strongly expanding in one direction (trending market), price can "walk the band" — staying at the upper or lower band for extended periods.

Bollinger Bands + RSI Combo

A powerful combination: price touches the lower Bollinger Band + RSI below 30 = high-probability buy signal in ranging markets. Price touches upper band + RSI above 70 = sell signal.

For trending markets: use the middle band (20 SMA) as dynamic support/resistance. In uptrends, pullbacks to the middle band are buying opportunities. In downtrends, rallies to the middle band are shorting opportunities.

Key Takeaways

  • Bollinger Bands measure volatility — expanding = high vol, contracting = low vol
  • The Squeeze (narrow bands) signals an imminent major move — direction unknown until breakout
  • Mean reversion works in ranging markets — price bounces between upper and lower bands
  • In trends, price can 'walk the band' — don't fade strong trending moves
  • Combine with RSI for high-probability entries at band touches
  • The middle band (20 SMA) acts as dynamic support/resistance in trends