Bollinger Bands: Volatility, Breakouts and Reversals

Most indicators measure price direction or momentum. Bollinger Bands measure something different: volatility. They answer the question that other indicators cannot: is the market currently compressed and likely to expand, or is it extended and likely to contract?

That single piece of information changes how every setup on the chart should be interpreted. A breakout in a compressed market is a high-quality signal. A breakout after extended expansion is a lower-quality one.

By the end of this chapter, you will be able to:

• Interpret Bollinger Bands (20,2) to assess the current volatility state of any stock.
  
• Identify the Bollinger Squeeze as a setup condition preceding breakouts.
  
• Recognise price walking the band as a trend strength signal.
  

How Bollinger Bands Work

Bollinger Bands consist of three lines: a 20-period Simple Moving Average (the middle band) and upper and lower bands set at two standard deviations from the middle band. The bands expand when volatility is high and contract when volatility is low.

When the bands contract to their narrowest point in several months, this is the Bollinger Squeeze. It indicates that the market has been in a low-volatility consolidation phase and that a significant directional move is building. The squeeze does not tell you which direction the breakout will occur. Volume and price action confirm the direction.

A pressure cooker builds internal pressure silently as it heats. The whistle stays still during the build-up. When pressure is sufficient, the whistle releases in a strong, sustained burst. A Bollinger Squeeze is that pressure build-up. The breakout candle is the whistle going off.

How the Bollinger Squeeze develops into a trade starting around a stock trading at ₹500:

Common Mistakes

Mistake 1: Treating price touching the upper band as an immediate sell signal

Price running along the upper band in a strong uptrend is a sign of trend strength, not overbought conditions. Selling into a band touch in a strong trend means selling the strongest part of the move.

Mistake 2: Entering a squeeze breakout without volume confirmation

The squeeze indicates a breakout is coming. Volume on the breakout candle determines whether it is genuine. A squeeze breakout on below-average volume is high false-breakout risk.

Key Takeaways

• Bollinger Bands (20,2) measure volatility through band width. Narrow bands signal low volatility and a probable breakout. Wide bands signal extended volatility.
  
• Price walking the upper band is a strength signal, not an overbought signal. The middle band is the mean reversion target during pullbacks.
  
• A Bollinger Squeeze identifies the setup condition. Volume and direction confirm the breakout. Trade the breakout, not the squeeze itself.
  

Assignment

Add Bollinger Bands (20,2) to the Nifty 50 daily chart. Go back six months and find every period where the bands were noticeably narrower than their recent average (a Bollinger Squeeze).

For each squeeze you find:
(1) In which direction did price break out?
(2) Was volume above average on the breakout candle?
(3) How far did price move after the breakout?
Track these observations in a table.

_We have now covered the core indicators for swing trading. In the next module, we step back to ask whether fundamental analysis has any role in a swing trader's process — and how to use it as a quick filter without overcomplicating things. (The specific Bollinger Bands setups are covered later, in the Strategy Playbook.) _

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