Bollinger Bands vs RSI
Bollinger Bands measure volatility: how widely price is swinging around its 20-day average. RSI measures momentum: how fast price has been rising or falling. A touch of the upper band and an RSI above 70 can look similar, but they mean different things, and together they give a fuller picture.
| Point | Bollinger Bands | RSI |
|---|---|---|
| What it measures | Volatility around a 20-day average | Speed of recent price moves |
| Where it appears | On the price chart | In a panel under the chart |
| Key signals | Squeeze, close outside a band, band rejection | Above 70, below 30, divergence |
| Tells you direction? | Not by itself; the breakout shows it | Shows strength of recent moves |
| Adapts to the stock | Yes, bands widen and narrow | Fixed 70/30 levels |
| Best at | Spotting calm before a big move | Spotting a stretched or tiring move |
How each one works
Bollinger Bands draw a channel around a 20-day average. The bands widen when price swings a lot and tighten when it goes quiet. A squeeze, when the bands get very narrow, means volatility is unusually low, and quiet periods tend to end with a sharp move.
RSI is a 0 to 100 score. Above 70 is overbought; below 30 is oversold. It says how fast the move was, not that it must end.
Where they disagree
In a strong breakout, price can close above the upper band day after day while RSI stays above 70. Both look “stretched”, yet the trend continues. Treating every upper-band touch or high RSI as a sell signal is a common mistake.
The useful moments are when they disagree. If price touches the upper band again but RSI makes a lower high, momentum is fading even as price pokes higher.
A worked example
Say a stock trades between ₹250 and ₹256 for three weeks and the bands squeeze tight. RSI sits near 50, giving no clue. Then price closes at ₹266, above the upper band, on about three times normal volume, and RSI jumps to 68. The bands flagged that a move was coming; RSI and volume showed it had force behind it.
When to use which
Use Bollinger Bands to see when a stock is unusually quiet or unusually stretched. Use RSI to judge the strength of the move and spot divergence. They measure different things, so combining them adds real information.
Common questions
Is RSI better than Bollinger Bands?
They do different jobs. Bollinger Bands track volatility, RSI tracks momentum, so neither replaces the other.
Does touching the upper Bollinger Band mean sell?
No. In a strong trend price can ride the upper band for a long time. A rejection from the band, with fading momentum, is more meaningful.
What is a Bollinger squeeze?
It is when the bands become very narrow because price has gone quiet. It often comes before a sharp move, and the breakout shows the direction.
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