Bollinger bands percent
Expresses where price sits relative to the Bollinger Bands as a single number — roughly 1 at the upper band, 0 at the lower — making “how stretched is price” easy to read as one line.
What the numbers mean
The same two settings as the bands themselves — %b just expresses where price sits between them as one number: 1.0 at the upper band, 0.0 at the lower, 0.5 at the middle average, and beyond that range when price trades outside the bands.
- 1.0 — price is exactly at the upper band
- 0.5 — price is on the middle 20-period average
- 0.0 — price is at the lower band
- Above 1 or below 0 — price is trading outside the bands entirely
- Settings mirror the bands themselves: 20 and 2 deviations
How it is used
Useful for comparing how stretched two different securities are on the same scale, and for rule-based systems where 'price closed above the upper band' has to be a number rather than a picture.
- Rule-based systems use %b because “outside the band” becomes a number
- Comparing %b across securities puts very different prices on one scale
- %b above 1 while RSI diverges → a frequently watched exhaustion combination
How it relates to everything else
%b is Bollinger Bands restated as an oscillator, so it sits naturally next to RSI and stochastics on the lower panel. The catch is that it says nothing about width: 0.9 during a squeeze and 0.9 during a volatility expansion are the same number but very different distances in dollars, which is why traders plot bandwidth alongside it.
- %b = where price sits · bandwidth = how wide the bands are; read both
- Behaves like an oscillator, so it compares directly with RSI and stochastics
- Inherits every limitation of the bands underneath it
What to watch for
It inherits every limitation of the bands and adds one: the reading depends entirely on band width, so 0.9 in a squeeze and 0.9 in a volatile expansion describe very different distances in dollars.