# Keltner Channels A Volatility concept (Band & channel systems) in the LuxAlgo Library, with 1 indicator implementation. ## What are Keltner Channels? Keltner Channels are volatility bands drawn around a moving average with the offset set by average true range: a midline (commonly a 20-period [EMA](https://www.luxalgo.com/library/concept/ema/)) plus an upper and lower band at the midline plus or minus a multiplier (commonly 1.5 to 2) times [ATR](https://www.luxalgo.com/library/concept/atr/). The name comes from Chester Keltner, whose 1960 version used a simple moving average of typical price offset by the average daily range; the EMA-and-ATR form in common use today was popularized decades later by Linda Bradford Raschke. The evolution is worth knowing because both versions still circulate. Keltner published his ten-day moving average trading rule in a 1960 commodities book, offsetting by the plain average of daily ranges; the modern rewrite swapped in the exponential midline and Wilder's true range, which folds opening gaps into the offset. Platforms differ in defaults and occasionally in which construction they implement, so two charts labeled Keltner can disagree. Because ATR is itself a smoothed measure that includes gaps, Keltner Channels widen and tighten more gradually than [Bollinger Bands](https://www.luxalgo.com/library/concept/bollinger-bands/), whose standard-deviation width reacts sharply to volatility clusters. That steadiness is the point: the channel gives a calmer definition of normal distance from the mean, which suits trend-following reads (price traveling between the midline and an outer band) and makes it the reference container in the [TTM Squeeze](https://www.luxalgo.com/library/concept/ttm-squeeze/), where Bollinger Bands contracting inside the Keltner Channel defines compression. Reading the channel is mostly reading the midline and the touches. The midline's slope carries the bias; in a healthy trend price oscillates between the midline and the outer band on the trend's side, and a persistent walk along that band marks strength rather than overextension. Channel width itself is a volatility dial: gradual widening accompanies developing trends, while contraction marks compression, the Keltner-side reading of [range expansion and contraction](https://www.luxalgo.com/library/concept/range-expansion-contraction/). ## How to calculate Keltner Channels The modern construction takes three inputs: a midline length, an ATR length, and a multiplier. 1. Compute the midline: a 20-period EMA of closing price is the common modern choice (Keltner's original used a 10-period SMA of typical price). 2. Compute ATR over its own lookback, often 10 to 20 periods, so the offset reflects recent true range including any gaps. 3. Set the bands: upper = midline + multiplier × ATR and lower = midline - multiplier × ATR, with 1.5 to 2 as typical multipliers. 4. Tune to the instrument: a multiplier that contains most candles on one market can be far too tight or loose on another, so calibrate by inspection or testing rather than assuming defaults transfer. 5. Then read the state: midline slope for bias, touches and band walks for trend strength, and width changes for the compression-expansion cycle. ## How it's calculated A volatility channel that wraps an EMA basis with bands offset by a multiple of Average True Range. ``` Middle_t = EMA_n(C_t) TR_t = max(H_t - L_t, abs(H_t - C_prev), abs(L_t - C_prev)) ATR_t = Wilder smoothed average of TR_t over the last p bars Upper_t = Middle_t + m × ATR_t Lower_t = Middle_t - m × ATR_t C_t: close at bar t H_t: high at bar t L_t: low at bar t C_prev: close on the prior bar t: current bar index EMA_n: exponential moving average over n bars n: basis EMA length (default 20) Middle_t: middle line of the channel TR_t: true range at bar t ATR_t: Average True Range at bar t p: ATR length (commonly 10) m: ATR multiplier (default 2) Upper_t: upper channel line Lower_t: lower channel line ``` Wilder smoothing: ATR_t = ((p - 1) × prior ATR + TR_t) / p; some platforms use an EMA or SMA of TR instead. These are the Linda Raschke settings most platforms implement; common defaults are n = 20, m = 2, and p = 10 or 14. Chester Keltner's 1960 original used a 10-day SMA of typical price (H + L + C) / 3 with bands offset by the 10-day SMA of H - L. ## How traders use it - As a trend channel: in a healthy trend price tends to travel between the midline and the outer band, with pullbacks to the midline acting as [dynamic support or resistance](https://www.luxalgo.com/library/concept/dynamic-s-r-via-ma/) for continuation entries. - As a breakout trigger: a close beyond a band marks movement beyond recent average range, which trend traders read as strength to join rather than fade; in ranges, the same close more often flags overextension. - As the container in squeeze logic: Bollinger Bands trading inside the Keltner Channel defines compression, the condition behind the TTM Squeeze family of setups. - As a stop or exit rail: the midline or the opposite band serves as a trailing reference that adapts to volatility, similar in spirit to other ATR-based trailing methods. - As a regime dial: tracking channel width against its own history, the Keltner analog of Bollinger [BandWidth](https://www.luxalgo.com/library/concept/bandwidth/), flags whether the market is compressing toward a break or already extended, before any directional read is attempted. ## Keltner Channels vs related concepts - **Bollinger Bands** (https://www.luxalgo.com/library/concept/bollinger-bands/): Bands scaled by the standard deviation of price rather than ATR, so they flare and pinch faster. Keltner width is smoother and folds gap risk in through true range. Many traders run both and trade their interaction. - **ATR Bands** (https://www.luxalgo.com/library/concept/atr-bands/): The generic form of the same idea: ATR offsets around any baseline. Keltner Channels are effectively the canonical parameterization (EMA midline, roughly 1.5 to 2 × ATR), and the two names are sometimes used interchangeably. - **STARC Bands** (https://www.luxalgo.com/library/concept/starc-bands/): Stoller's channel also offsets by ATR, but around a short simple moving average, and is traditionally read for counter-trend band-tag trades rather than for trend riding. ## FAQ ### What are the standard settings for Keltner Channels? The common modern setup is a 20-period EMA midline with bands at 2 × ATR (1.5 is also widespread), using an ATR lookback of roughly 10 to 20 periods. Chester Keltner's original 1960 rule used a 10-day SMA of typical price offset by the average daily range. Treat all of these as starting points to calibrate per market. ### Keltner Channels or Bollinger Bands: which should I use? They answer slightly different questions. Bollinger Bands scale with the standard deviation of closes, so they react quickly to volatility bursts; Keltner Channels scale with smoothed true range, so they move steadily and account for gaps. Neither is universally better. Trend traders often prefer Keltner's stability, while squeeze systems deliberately use both together. ### What does it mean when price closes outside a Keltner Channel? It means the move exceeded a multiple of recent average true range, which is relatively uncommon with typical multipliers. In a trending market that is often read as strength and potential continuation; in a sideways market it is more often read as overextension that may mean-revert. The close is context, not a standalone signal, so pair it with regime and structure. ### Can Keltner Channels be used for mean reversion? Yes, in the conditions that suit it: inside ranges, tags of the outer bands are faded back toward the midline, with the channel providing both the entry zone and the target. The same trade taken in a trending market is the classic mistake, since trends walk along a band by design. Most reversion users gate the setup with a regime filter before trusting a band tag. ### Why use ATR instead of standard deviation for the bands? True range includes gaps and is conventionally smoothed with a slow average, so an ATR offset changes gradually and represents how far bars actually travel. Standard deviation reacts quadratically to outliers, which makes Bollinger widths flare and pinch abruptly. Neither is wrong; ATR gives the calmer container, which is what trend-following and squeeze-container roles want. ### What is a Keltner band walk? A sequence of bars pressing along the upper (or lower) band with shallow pullbacks that hold above the midline. It is the signature of a strong trend: price staying beyond one full ATR multiple from the mean for bar after bar. Band walks are why closes outside the channel are read as strength in trends, and why counter-trend fades are reserved for confirmed range conditions. ## Implementations in the Library - Keltner Channels (LuxAlgo, the standard build of the classic formula): https://www.luxalgo.com/library/indicator/keltner-channels/ ## Related concepts - Donchian Channels: https://www.luxalgo.com/library/concept/donchian-channels/ - Envelope: https://www.luxalgo.com/library/concept/envelope/ - Bollinger Bands: https://www.luxalgo.com/library/concept/bollinger-bands/ - %B: https://www.luxalgo.com/library/concept/percent-b/ - BandWidth: https://www.luxalgo.com/library/concept/bandwidth/ - Bollinger Squeeze: https://www.luxalgo.com/library/concept/bollinger-squeeze/ - Band Walk: https://www.luxalgo.com/library/concept/band-walk/ - Bollinger Band Tag Reversion: https://www.luxalgo.com/library/concept/bollinger-band-tag-reversion/ - Double Bollinger Zones: https://www.luxalgo.com/library/concept/double-bollinger-zones/ - Fibonacci Bollinger Bands: https://www.luxalgo.com/library/concept/fibonacci-bollinger-bands/ --- Source: https://www.luxalgo.com/library/concept/keltner-channels/ (LuxAlgo Library, the encyclopedia of trading & technical analysis). Free to use with attribution: https://www.luxalgo.com/library/license/