Donchian Channels can be useful in visualizing the volatility of a market's price action. If the price is stable, the Donchian Channel will be relatively narrow. If the price has large fluctuations, the Donchian Channel will be wider.
Using the 20 day default period, a move above the channel signals a new 20 day high. Similarly, using a 20 week period, a move above the channel would signal a new 20 week high. Markets that continuously touch or exceed the upper channel line show strength, while conversely markets that continuously touch or break below the lower channel line show weakness.
Learn how Donchian Channels can improve your trading here.