Advance/Decline Volume Line

The Advancing-Declining Volume Line (AD Volume Line) is a breadth indicator
based on Net Advancing Volume, which is the volume of advancing stocks less
the volume of declining stocks. Net Advancing Volume is positive when advancing
volume exceeds declining volume and negative when declining volume exceeds
advancing volume. The AD Volume Line is a cumulative measure of Net Advancing
Volume. It rises when Net Advancing Volume is positive and falls when Net
Advancing Volume is negative. Chartists plot the AD Volume Line for a specific
index and compare it to the performance of that index. The AD Volume Line should
confirm an advance or a decline with similar movements. Bullish or bearish
divergences in the AD Volume Line signal a change in buying or selling pressure
that could foreshadow a reversal in the index.