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Keltner Channels (kc)

[[kc]] produces three series: a middle line and two bands that form an adaptive envelope around it. The middle line is an exponential moving average of source, representing the smoothed level of that series. The upper and lower bands remain equally distant from this center.

The spacing between the bands follows recent candle ranges, widening as those ranges expand and narrowing as they contract. length sets the smoothing horizon for both the center and the spacing, while multiplier controls the distance of the bands. use_true_range selects either True Range, which accounts for gaps from the previous close, or the candle’s high - low range alone.

Block declaration

A strategy can contain multiple [[kc]] blocks. Each block produces three series: upper channel, middle line, and lower channel. Each series is identified using the keys upper_id, middle_id, and lower_id.

Examples

Minimal setup

This block computes Keltner Channels using the block defaults: source = "close", length = 20, multiplier = 2.0, and use_true_range = true.

[[kc]]
upper_id  = "kc_up"
middle_id = "kc_mid"
lower_id  = "kc_low"

Custom fixed setup

This block uses hl2 for the middle line, a 14-candle window, a 1.5 multiplier, and the simple high - low range instead of True Range.

[[kc]]
upper_id       = "kc_up"
middle_id      = "kc_mid"
lower_id       = "kc_low"
source         = "hl2"
length         = 14
multiplier     = 1.5
use_true_range = false

Search for the optimal period and multiplier

This block explores ranges of values for length and multiplier to identify the best-performing combination.

[[kc]]
upper_id  = "kc_up"
middle_id = "kc_mid"
lower_id  = "kc_low"

length.start = 10
length.stop  = 30
length.step  = 1

multiplier.start = 1.0
multiplier.stop  = 3.0
multiplier.step  = 0.25

Channel breakout filter

This example uses the upper band as a breakout filter. On each candle, the [[condition]] block only lets the strategy move on when close > kc_up, meaning price closes above the upper channel.

[[kc]]
upper_id  = "kc_up"
middle_id = "kc_mid"
lower_id  = "kc_low"

[[condition]]
id            = "channel_breakout"
condition     = "close > kc_up"
next_block_id = "..."

Dedicated symbol and timeframe

This Keltner Channels block uses the daily candles from BINANCE:ETHUSDT. The middle line and the high, low, and close prices needed for the range come from this symbol and timeframe, independently of the primary symbol and timeframe defined in [backtest]. See Exchanges, Symbols and Timeframes for alignment rules.

[[kc]]
upper_id   = "kc_up"
middle_id  = "kc_mid"
lower_id   = "kc_low"
symbol     = "BINANCE:ETHUSDT"
timeframe  = "D"

Parameters

ParameterDescription
upper_id
 String
 Required		Name of the upper channel series.
Example: upper_id = "kc_up"
middle_id
 String
 Required		Name of the middle line series.
Example: middle_id = "kc_mid"
lower_id
 String
 Required		Name of the lower channel series.
Example: lower_id = "kc_low"
source
 String
 or Array
 Optional		Input series used to calculate the middle EMA line.
Accepted forms: source = "hl2" or source = ["close", "hl2"].
Each value can be either a standard price source (open, close, high, low, hl2, hlc3, ohlc4, hlcc4, volume) or the id of another indicator.
Default value: "close"
length
 Integer
 Optional		Period used for both the middle-line EMA and the range EMA; must be at least 1. Default value: 20.

Usage:
• Fixed: length = value with value >= 1
• Grid search:
 – length.start = min_value with min_value >= 1
 – length.stop = max_value
 – length.step = value (optional, default 1)
multiplier
 Decimal
 Optional		Multiplier applied to the range EMA to calculate the upper and lower bands; must be strictly greater than 0. Default value: 2.0.

Usage:
• Fixed: multiplier = 2.0
• Grid search:
 – multiplier.start = min_value with min_value > 0
 – multiplier.stop = max_value
 – multiplier.step = value (optional, default 1)
use_true_range
 Boolean
 Optional		Selects the range used for the channel width.
If true, the block uses True Range. If false, it uses high - low.
Default value: true
symbol
 String
 or Array
 Optional		Market symbol(s) used for the high, low, and close prices needed by the range, and for source when source contains standard price series.
If source references another indicator, symbol does not replace that source series; it still applies to the high, low, and close prices used for the channel width.
If omitted, the block inherits the [backtest] symbol.
For symbol format, arrays, and alignment rules, see Exchanges, Symbols and Timeframes.
timeframe
 String
 or Array
 Optional		Timeframe on which this indicator is computed.
If timeframe is omitted, the computation uses the grid’s main timeframe defined in [backtest].
For accepted formats and timeframe alignment rules, see Exchanges, Symbols and Timeframes.

Available variables

Use the identifiers below directly in your expressions. The Keltner Channels block exposes three numeric series (upper, middle, lower), their parameters, the middle-line input series, the price sources used for the range, the symbol, and the timeframe.

Assume the block is configured as:

[[kc]]
upper_id  = "kc_up"
middle_id = "kc_mid"
lower_id  = "kc_low"

Then:

VariableDescription
kc_up or kc_up[0]
Decimal		Current upper channel value.
kc_mid or kc_mid[0]
Decimal		Current middle EMA line value.
kc_low or kc_low[0]
Decimal		Current lower channel value.
kc_up[n]
kc_mid[n]
kc_low[n]
Decimal		Upper channel value from n candles ago.
Middle line value from n candles ago.
Lower channel value from n candles ago.
kc_up.length
kc_mid.length
kc_low.length
Decimal		Period used for the middle-line EMA and the range EMA.
kc_up.multiplier
kc_mid.multiplier
kc_low.multiplier
Decimal		Multiplier applied to the range EMA.
kc_up.use_true_range
kc_mid.use_true_range
kc_low.use_true_range
Decimal		Range calculation mode: 1 when True Range is used, 0 when the block uses high - low.
kc_up.source
kc_mid.source
kc_low.source
String		Name of the series used for the middle EMA line.
kc_up.high_source
kc_mid.high_source
kc_low.high_source
String		Name of the high series used to calculate the range.
kc_up.low_source
kc_mid.low_source
kc_low.low_source
String		Name of the low series used to calculate the range.
kc_up.close_source
kc_mid.close_source
kc_low.close_source
String		Name of the close series used to calculate True Range when use_true_range = true.
kc_up.symbol
kc_mid.symbol
kc_low.symbol
String		Symbol used by this output.
kc_up.timeframe
kc_mid.timeframe
kc_low.timeframe
String		Timeframe used by this output.

Notes

  • The bands are calculated symmetrically around the middle line: upper channel = middle + multiplier × EMA(range) and lower channel = middle - multiplier × EMA(range).
  • Numeric variables support arithmetic, comparisons, and logical operators.
  • Text variables are strings intended for equality/inequality checks only.
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