Both Plus Directional Movement (+DM) and Minus Directional Movement (-DM) are negative and revert to zero, in order that they cancel each other out. All inside days will have zero directional movement. Although Wilder designed his Directional Movement

Various market timing methods have been devised using ADX. One of those strategies is mentioned by Alexander Elder in his book Trading for a Living. One of the best buy signals is when ADX turns up when below both Directional Lines and +DI is above -DI