Divergence is a discrepancy in the price chart and indicator in which the chart is headed up and the oscillator line is headed down.
In other words, they move in the opposite direction, away from one another.
If there is divergence between the chart and Detrended Price Oscillator, the trend might reverse and the price will start to fall.
Divergence, like convergence, is a secondary signal.
I don’t recommend opening trades on the basis of it alone.