%B (Bollinger Bands %B)¶
What it shows: where the close sits inside the Bollinger Bands: 0 at the lower band, 1 at the upper band, 0.5 in the middle. Below 0 or above 1 means outside the bands.
How people use it: below 0 (close under the lower band) is read as oversold; above 1 as overbought. It turns band touches into a number you can compare.
Pairs well with: RSI and ADX, as with Bollinger Bands.
Settings¶
| Setting | Default | What it does |
|---|---|---|
| Length | 20 | Length of the Bollinger Bands. |
| Std dev | 2.0 | Width of the bands. Wider reaches 0 and 1 less often. |
| Oversold | 0 | The "low" level (0 = lower band). |
| Overbought | 1 | The "high" level (1 = upper band). |
You set the defaults on the Indicators page. A condition can use its own settings, which override the defaults for that condition only.
Ready-made conditions¶
| For | Condition | Fires when |
|---|---|---|
| Buy | %B below 0 | every candle %B is below 0 |
| Buy | %B crosses above 0 | the one candle %B moves from below 0 to above it |
| Sell | %B above 1 | every candle %B is above 1 |
| Sell | %B crosses below 1 | the one candle %B moves from above 1 to below it |
"Above", "below", "is" and "rising" / "falling" stay true on every candle the state lasts, so they can fire many candles in a row. "Crosses" and "flips" fire once, on the candle it happens, so you get one signal per move. Numbers in the condition names follow your settings on the Indicators page.
Warnings you may see¶
- "It can never be true: a cross happens on one candle, so it cannot happen on N candles in a row. Use 'within the last N candles' instead.": a "crosses" condition with a "… in a row" lookback of 2 or more. Switch the lookback to Within the last.
- "Length must be between 1 and 1000" / "Length must be a whole number": shown in the condition editor when a condition's own value is out of range. Fix the number; the condition can't be saved until then.
- "Std dev must be between 0.1 and 10": shown in the condition editor when a condition's own value is out of range. Fix the number; the condition can't be saved until then.
Where they show: on the Strategies page, open Create entry conditions / Edit entry conditions (or the exit ones). Each condition's messages appear right under it. The setting messages ("must be between", "whole number", "must be one of", "must be smaller than") start with the indicator's short name, for example "MACD: Fast must be between 1 and 1000", and keep the conditions from being saved until fixed. The other warnings never block saving and are repeated in the strategy's Entry or Exit section, starting with the condition's name.
Good to know¶
- It is worked out from closing prices only (not volume).
- When the last closes are all equal the bands have no width and %B is unavailable (conditions on it are false).
- It needs some history before its value settles: the length in candles (20 at length 20). Apathia loads that history for you.