Donchian Channel
Highest high and lowest low over N bars — foundational breakout indicator.
What it is
The Donchian Channel is the simplest of band indicators: the upper line is the highest high of the last N bars; the lower line is the lowest low. The middle line is their average. Popularized by Richard Donchian in the 1950s and made famous by the legendary "Turtle Traders" trend-following system in the 1980s.
The simplicity is the point. Donchian asks one question: has price made a new N-bar extreme? When the answer is yes, a breakout has occurred. This is one of the oldest systematic-trading concepts in existence and forms the spine of countless trend-following strategies.
How it's calculated
For an N-period Donchian (default 20):
Upper = max( High over the last N bars ) Lower = min( Low over the last N bars ) Middle = (Upper + Lower) / 2
The conventional definition uses the previous N bars *excluding* the current bar — otherwise every new extreme would be confirmed by itself.
How to interpret signals
Breakouts. Close above the upper line = bullish breakout. Close below the lower = bearish breakout. This is the entry trigger for classic trend systems.
Mean reversion. Some strategies fade Donchian extremes, betting that overshoots get bought back. This works in range-bound regimes but fails in trends.
Channel as visualization. Width tells you about volatility/range expansion. A flat channel followed by a breakout is a classic setup.
Strengths
- Conceptually the simplest band indicator — one bar of explanation.
- Battle-tested by famous trend-following systems (Turtles, Donchian's own work).
- No smoothing or magic constants beyond the period.
- Clear binary breakout signals, easy to backtest objectively.
Limitations
- Most breakouts are false in non-trending markets — the cost of waiting for genuine trends.
- Period choice (20 vs 55) drastically affects signal frequency and quality.
- Equal-weighted by definition — recent bars do not get more weight than old ones in the window.
- Single outlier bar can set the threshold, producing fragile breakout levels.
Common pitfalls
- Trading every Donchian breakout without trend, volume, or volatility confluence.
- Using too-short period (e.g., 10) on intraday — too many false breakouts.
- Combining with another breakout indicator that lags more (defeats the purpose).
- Skipping confirmation bars — a single-bar breakout often reverses immediately.
Related strategies in Backstrap
Educational note: This page explains what DC measures and how it is conventionally interpreted. It does not constitute investment advice. Past patterns do not guarantee future results, and no indicator works in all market regimes. See the full disclaimer.
Last updated: 2026-05-08