Directional Movement is a system for discovering trading signals to be used for price breaks from a trading range. It involves 5 indicators: Directional Movement Index (DX), the plus Directional Indicator (+DI), the minus Directional Indicator (-DI), the Average Directional Movement (ADX) and the Average Directional Movement Rating (ADXR).

Wilder defines -DI as the percentage of the true range that is down. When the -DI is greater than +DI, a short position is indicated.

Information provided by Charles LeBeau's Technical Traders Guide to Computer Analysis of the Futures Market.