# Bollinger Bands

> A moving-average basis with an upper and lower band set a chosen number of standard deviations away, so the envelope itself reads volatility.

Bollinger Bands draw **a moving average with a band above and below it**, each set a number of standard deviations of price away. When the market gets quiet the bands pinch together. When it starts moving they spread apart. So the envelope is a volatility read on its own: a tight squeeze on QQQ after a slow lunch often comes before the afternoon move, though it won't tell you which way.

A tag of the upper or lower band means price is stretched relative to its recent range. In a range that's often where moves stall. In a strong trend, price can walk along one band for a long time.

![Bollinger 20 2 on NQ 5m: tight bands through a quiet morning, then wide bands as the selloff expands range](https://www.skylit.ai/docs/images/atlas/indicators/bollinger-bands.light.webp)

*NQ 5m, Oct 16, 2026 · Atlas*

## Adding the indicator

Open the chart settings panel and use the **Add** button in the Indicators section. It's listed as **Bollinger** in the **Overlay** group. Each instance gets its own settings cog and can be removed the same way.

## Settings

| Setting | Options | What it controls |
| --- | --- | --- |
| Period | **20** (default), any whole number from 1 to 5,000 | The window for both the basis average and the standard deviation. |
| Std dev | **2** (default), above 0 up to 10 | How many standard deviations out the bands sit. Higher means a wider envelope and rarer tags. |
| Basis line | Colour, width (1 to 4), style, opacity | The middle line. Solid by default. |
| Upper and lower lines | Colour, width (1 to 4), style, opacity | Each band styled on its own. Dashed by default. |
| Label | **Always** (default), On hover, Off | The price-axis badges and the name on the chart. The crosshair readout keeps showing all three values either way. |

## Reading notes

- **All three lines share one window.** The basis is a simple average of the last N closes, and the bands are measured from the spread of those same closes.
- **It's built from the close,** so the forming bar's bands move until that bar closes.
- **The row label shows both numbers.** An instance reads "Bollinger 20 · 2", so a 20 · 2 and a 20 · 3 on the same chart are easy to tell apart.
- **Want the candles flagged for you?** The [RSI × Bollinger Combo](https://www.skylit.ai/docs/atlas/indicators/rsi-bollinger-combo) colours the candles that close outside the bands while RSI agrees.