Donchian Channel

Donchian Channels are among the simplest technical indicators to compute:

Upper band = Highest high of the last N periods (default N = 20) Lower band = Lowest low of the last N periods Middle line = (Upper band + Lower band) / 2

No smoothing, no weighting, no complex formulas. The upper band only moves up when price makes a new N-period high; the lower band only moves down when price makes a new N-period low. Between new highs and new lows, the bands remain flat — creating a staircase pattern that makes breakout levels crystal clear.

Common period settings:

• 20-day Donchian: The original Turtle Trading entry signal. Represents roughly one month of price history. A breakout above the 20-day high means the stock is at its highest price in a month.
• 55-day Donchian: The longer-term Turtle entry. Roughly one quarter of price history. Used for catching major trend changes.
• 10-day Donchian: The Turtle exit signal. When price drops below the 10-day low after entering on a 20-day high breakout, exit the trade.
• 5-day Donchian: Intraday traders use 5-period Donchian on hourly charts to identify short-term breakout levels.

The beauty of Donchian Channels is their objectivity. There is no discretion in the calculation — the highest high and lowest low are facts, not interpretations.

The most famous application of Donchian Channels is the Turtle Trading experiment conducted by Richard Dennis and William Eckhardt in 1983. Dennis believed trading could be taught; Eckhardt disagreed. They recruited 23 people, taught them a trend-following system based on Donchian Channels, and gave them real money to trade. The Turtles earned over $175 million in aggregate.

Entry rules: Buy when price closes above the 20-day high (upper Donchian band). Short when price closes below the 20-day low. An alternative entry uses the 55-day channel for catching larger trends.

Exit rules: Exit long positions when price drops below the 10-day low. Exit short positions when price rises above the 10-day high. This asymmetry (enter on 20-day, exit on 10-day) gives winning trades room to run while cutting losing trades relatively quickly.

Position sizing: The Turtles used ATR-based position sizing — risking 2% of account equity per trade with stop distance set at 2x ATR. Multiple positions were added as the trade moved favorably, building into winners.

Why it worked: The system captured large trends by design. Most individual trades lost money (win rate around 35-40%), but the winners were dramatically larger than the losers. A single trend-following trade in a major market move could generate 20x the average loss. The math of positive expectancy, not prediction accuracy, drove returns.

Modern relevance: While the exact Turtle system is less effective in modern, algorithmic markets (breakout signals are crowded), the underlying principles remain sound: trade breakouts in trending conditions, cut losses quickly, let winners run, and size positions based on volatility.

Classic breakout: Enter long when price closes above the upper Donchian band; enter short when price closes below the lower band. Require a close outside the band, not just an intraday wick — this reduces false breakouts. Add a volume filter (relative volume above 1.5x) for higher-probability entries.

Channel width as volatility filter: When the upper and lower bands are close together (narrow channel), the stock has been range-bound. A breakout from a narrow channel is more significant than a breakout from a wide one because compressed volatility tends to resolve with explosive moves. Measure channel width as (Upper - Lower) / Middle and look for breakouts when width is in the bottom 20% of its recent history.

Donchian with regime filter: Donchian breakouts work in trending markets but generate whipsaws in choppy markets. Combine with a trend filter: only take long breakouts when the 50-day moving average is above the 200-day, or when the ADX is above 25. This dramatically reduces false breakout entries.

Multi-timeframe Donchian: Use the weekly 20-period Donchian for trend direction and the daily 20-period for entries. Only take daily breakouts in the direction of the weekly trend. This ensures you are trading with the larger trend rather than catching counter-trend noise.

Pullback entry within the channel: Instead of buying at the upper band (breakout), wait for a breakout followed by a pullback to the middle line. Enter on the pullback with a stop below the lower band. This offers better risk/reward at the cost of missing some breakouts that never pull back.