The Average Directional Index, or ADX, is a trend indicator that is used to quantify the strength of a trend. It is plotted as a single line with a value between 0 and 100. Unlike other trend indicators the ADX is non-directional, meaning it simply register the strength of the trend, not whether it is an up-trend or a down-trend. In order to indicate whether prices are moving higher or lower the ADX Indicator is plotted with the +DMI and –DMI lines from which the ADX is derived.