Bollinger Bands

Indicators core.bb Version 1.0.0

Average plus/minus k standard deviations. Like ta.bb: the middle band is the SMA, the bands sit k (population) standard deviations above and below. Touching the lower band signals strong selling.

Inputs and outputs

Only matching types connect: number series to number series (round pin), signal to signal (square), message to message (diamond).

Direction	Pin	Type	Note
Input	Value in	Number series	required
Output	Upper upper	Number series	in the unit of the input
Output	Middle middle	Number series	in the unit of the input
Output	Lower lower	Number series	in the unit of the input

Settings

The settings appear on the right under “Properties” once the node is selected on the board. Those marked “More” appear after clicking “More”.

Setting	Default	Allowed	Meaning
Periods length	20	from 2 to 500, whole number	–
Width (σ) mult	2	from 0.1 to 10	–

Example

Notifies you when the price drops below the lower Bollinger Band.

On the board it reads: 20 · 2 σ

Chain as JSON

To try it, copy it and paste it in the editor under “Import”. Importing creates a new chain.

bb.json

{
  "name": "Example: Bollinger Bands",
  "version": 1,
  "nodes": [
    { "id": "c1", "type": "core.candle", "position": { "x": 40, "y": 40 }, "settings": { "pair": "BTC/USDT", "timeframe": "1h" } },
    { "id": "b1", "type": "core.bb", "position": { "x": 260, "y": 40 }, "settings": {} },
    { "id": "k1", "type": "core.compare-ab", "position": { "x": 480, "y": 40 }, "settings": { "operator": "crossesBelow" } },
    { "id": "p1", "type": "core.push", "position": { "x": 700, "y": 40 }, "settings": {} }
  ],
  "edges": [
    { "from": "c1.close", "to": "b1.in" },
    { "from": "c1.close", "to": "k1.a" },
    { "from": "b1.lower", "to": "k1.b" },
    { "from": "k1.out", "to": "p1.in" }
  ]
}

Good to know

• In messages the values are called “upper band”, “middle band”, “lower band”.
• Warm-up with the default settings: 20 candles (this many extra candles are loaded by the replay before the value is reliable).
• Search also finds it under: volatility, band, squeeze, standard deviation.

Technical details

• Type in the chain: core.bb · Version 1.0.0 · Category key ind
• Reference tests in the manifest: 1 (with fixed price data binance-btcusdt-1h-500)
• How a node is built