Average Directional Index (ADX) is an indicator that measures the strength or weakness of the trend regardless of whether markets are moving up or down.
ADX value is calculated over a 14 day period and ranges between 0 to 100. If the stock prices have been falling and the ADX value moves above 25, it indicates that the trend is strengthening and prices will continue to fall. If in a rising market ADX value moves above 25, it indicates continued bullishness. An ADX value below 20 indicates no trend.