They are a set of indicators developed by Welles Wilder that are plotted with three lines ADX, DI+ and DI-.
The ADX is calculated from the Directional Movement Index.
The Directional Movement Index (DMI) is decomposed into DI+ (Positive Directional Index) and DI- (Negative Directional Index) and is a measure of the amount of movement upward or downward that have the prices.
Technical analysis refers to a set of techniques that try to predict stock prices from a historical perspective, taking into account the behavior of certain magnitudes securities, as trading volume and evolution of the prices. It is based on the behavior and psychology of investors and in the movement of prices. It is supported by the construction of charts showing the historical evolution of the prices of securities, analysis of figures and the use of oscillators and indicators.