Developed by Edwin Coppock, this indicator represents a further development of the Momentum or ROC. Here two time-weighted momentum curves are added and their long-term weighted moving average represents the Coppock Line.

The Coppock must be interpreted as an oscillator. Its conclusions apply only for the long term, and are thus used to determine trends lasting several years.

If the Coppock Indicator turns up while below the center line, this is regarded as a buy signal, whereas if it turns down while above the center line, this is viewed as a sell signal. Sell signals often come too early and need to be confirmed by other long-term indicators.