ADX, also known as the Average Directional Index, is a technical indicator on a chart that measures the strength of a trend in a trading instrument, whether it is trending up or down. The ADX shows whether an asset such as a currency pair, stock, or crypto is trending or not and how strong the trend is. This indicator is calculated based on the difference between the +DI and -DI lines. The ADX value ranges from 0 to 100. The higher the value, the stronger the trending signal. Values below 25 indicate the absence of a clearly defined trend. Reading ADX along with +DI and -DI is important to determine the direction of the trend.