Bollinger Bands

In one line: Bollinger Bands are elastic rails around price that tell you when the market is calm, when it is stretched, and when a big move may be waking up.

🎯 What you'll learn

What the three Bollinger lines are and how they are built.
How to read a squeeze (bands pinching together).
Why price bounces inside a range but rides the band in a trend.
Why touching the top band is not an automatic "sell".

📘 Key concepts

The three lines

Bollinger Bands are three lines drawn around price.

Middle band — usually a 20 SMA (Simple Moving Average — the average closing price of the last 20 days). Think of it as the "fair" recent price.
Upper band — the middle band plus 2 standard deviations. (Standard deviation = a number that measures how spread out prices are, i.e. how jumpy the market is.)
Lower band — the middle band minus 2 standard deviations.
So the bands are like the two sides of a road, and price is the car driving between them.

Bands breathe with volatility

Volatility (how much and how fast price moves) changes the width of the bands.

Calm market → prices stay close together → bands get narrow.
Wild market → prices swing a lot → bands get wide.
Picture a quiet shop at 3 PM (narrow) versus a busy bazaar at festival time (wide).

The squeeze

A squeeze is when the bands pinch into a tight, thin channel.
It means volatility is very low right now. The market is resting.
Low volatility often comes before a big move — like a coiled spring or a bowler pausing before a fast delivery.
The squeeze tells you a move may be coming, but not the direction. Wait for price to break out and confirm.

Range vs trend behaviour

How price uses the bands depends on the market mood.

In a range (price moving sideways between a floor and a ceiling), price often bounces off one band and drifts back to the middle band.
In a strong trend (price steadily going one way), price can "ride the band" — hugging the upper band while going up, or the lower band while going down.
Same tool, two very different messages. Always check the bigger structure first.

🔍 Example

Imagine a stock trading near ₹100.

Price
110 |            .-''-. upper (riding)
105 |   ___     /
100 |__/   \___/  <- squeeze (bands tight)
 95 |            \
 90 |             '--. lower
    +--------------------> time
      calm      breakout

For weeks price sits around ₹100. The bands squeeze tight to ₹98–₹102. Very calm.
Then buyers step in. Price jumps to ₹105, then ₹110. The bands widen fast.
Price now rides the upper band as the uptrend runs.
A beginner who sold at the first upper-band touch (₹104) missed the whole move. In a trend, touching the top is normal, not a sell signal.

⚠️ Common mistakes

Treating an upper-band touch as an automatic sell (or lower-band touch as an automatic buy). In a trend this is wrong.
Trading a squeeze before the breakout — you do not yet know the direction.
Using bands alone. They measure volatility and stretch, not "buy" or "sell".
Forgetting to check if the market is ranging or trending first.
Changing the settings often to force a signal. Keep the default 20 SMA, 2 standard deviations while learning.

✅ Key takeaways

Three lines: a 20 SMA middle, plus upper/lower bands 2 standard deviations away.
Bands widen in wild markets and narrow in calm ones.
A squeeze warns a big move may come, but not the direction.
In a range price bounces to the middle; in a trend it rides the band.
A band touch is information, not an order — combine it with structure.

📝 Quick check

Q: The bands have pinched into a very thin channel. What does that tell you? A: Volatility is low (a squeeze). A bigger move may be building, but you do not yet know the direction — wait for the breakout.
Q: Price touches the upper band during a strong uptrend. Is that an automatic sell? A: No. In a strong trend price often rides the upper band. A touch alone is not a sell signal.
Q: What is the middle band usually based on? A: A 20 SMA — the average closing price of the last 20 periods.

📖 New words

Bollinger Bands — three lines (middle, upper, lower) drawn around price to show volatility and stretch.
SMA (Simple Moving Average) — the average price over a set number of periods, here 20.
Standard deviation — a measure of how spread out or jumpy prices are.
Volatility — how much and how fast price moves.
Squeeze — when the bands pinch tight, showing very low volatility.
Riding the band — price hugging one band during a strong trend.
Range — a market moving sideways between a floor and a ceiling.
Trend — a market steadily moving one direction, up or down.

Educational content only — not financial advice. Trading involves the risk of losing money.