-DI indicates the bearish component of the historic series movement, and is typically used in conjunction with the other indicators of W.Wilder, ADX and +DI.

The interpretative theory also establishes the following rules:

In the case of ADX and -DI with increasing trends against a declining movement of the +DI the system expresses the intensification of a bearish trend;

if the ADX has a lateral or slightly decreasing trend, while +DI and -DI tend to a sort of convergence, the system shows the start of a congestion phase:

A decreasing ADX and the crossing of the +DI and -DI curves (-DI > +DI) confirm a distribution or redistribution;
The crossing of the +DI and -DI curves (with +DI > -DI) and a falling ADX confirm a phase of accumulation or reaccumulation.