 "Divergence" is when the stock market index moves in one direction while the ADL on that index moves in the opposite direction.If the index moves up while the ADL moves down, the index may be misleading about the true direction of the overall market, as happened toward the end of the US Dot-com bubble in 1999–2000, when the indices continued to rally while the ADL diverged downward starting at the beginning of 1999.Such negative divergence was also seen toward the end of the roaring twenties bull market, during 1972 at the height of the Nifty Fifty market, and starting in March 2008 before the late-2008 market collapse.