Keltner channel
The Keltner channel is a volatility envelope around a 20-period EMA, set two average true ranges above and below it — like Bollinger bands, but breathing with traded range rather than statistical deviation.
The modern Keltner channel wraps a 20-period EMA in bands placed two ATRs away on each side. Both choices matter: the EMA centre line leans toward recent price, and the ATR spacing means the envelope widens with the actual traded range — gaps included — rather than with the dispersion of closes. Since ATR carries Wilder's slow smoothing, the channel inflates and deflates gradually, holding its shape through single wild sessions that would flare a standard-deviation band.
That steadiness defines its use. A close above keltner().upper is a stock escaping a slow-moving definition of its normal range, which makes Keltner breakouts less frequent and less twitchy than Bollinger ones — fewer signals from one loud session. The other established use is the squeeze refinement: when the Bollinger bands contract inside the Keltner channel, close-price volatility has compressed even below the traded-range norm, the tightest coil either tool can describe on its own.
The cost of steadiness is lateness. Because ATR deflates slowly after a volatile spell, the channel stays wide for weeks, and moves that a Bollinger band would flag as exceptional pass quietly inside it; at genuine volatility regime changes Keltner is always the last to adjust. And like every envelope, it describes only where price sits relative to its own norm — in a persistent trend, price can walk along the upper band indefinitely.
The choice against Bollinger comes down to the volatility input: standard deviation reacts to surprise, ATR to traded range. Bollinger asks whether the close is statistically unusual; Keltner asks whether price has left the territory it normally covers in a day. Trend traders tend to prefer Keltner precisely because it is harder to trigger.
In Sift
Written as keltner().upper / .lower. A working scan — stocks closing above their ATR-based upper channel with volume behind the move:
where close > keltner().upper and rel_volume > 1.51
of the 500 most-traded NSE stocks match today, as of 20 Aug 2026
Common questions
What is the difference between Keltner channels and Bollinger bands?
Both wrap a 20-period average in volatility bands; the difference is the volatility measure and the centre line. Keltner uses two ATRs around an EMA, Bollinger two standard deviations around an SMA. ATR breathes slowly, so Keltner channels stay calm through single wild sessions where Bollinger bands flare — fewer signals, steadier ones.
What does a close above the Keltner channel mean?
Price has finished the day more than two average true ranges above its 20-day EMA — outside the territory its normal daily range covers. Traders read it as a breakout with more inertia than a Bollinger band close, because a slow-adjusting channel is harder to exceed. Whether such closes have followed through is checkable in the replay.