"Accumulation/distribution is a momentum indicator that attempts to gauge supply and demand by determining whether investors are generally "accumulating," or buying, or "distributing," or selling, a certain stock by identifying divergences between stock price and volume flow."
If a security's price is in a downtrend while the accumulation/distribution line is in an uptrend, the indicator shows there may be buying pressure and the security's price may reverse. Consequently, the security may reverse and trend up. Conversely, if a security's price is in an uptrend while the accumulation/distribution line is in a downtrend, the indicator shows there may be selling pressure, or high distribution. This may cause the security's price to reverse and turn into a downtrend