Accumulation/Distribution Line ( AD )
The Accumulation/Distribution Line was developed by Marc Chaikin to assess the cumulative flow of money into and out of a security. He decided to focus on the price action for a given period (day, week, month) and derived a formula to calculate a value based on the location of the close, relative to the range for the period. This is the "Close Location Value" or CLV. The CLV ranges from plus one to minus one with the center point at zero.
The signals for the Accumulation/Distribution Line are fairly straightforward and involve divergence or confirmation. A bullish signal is given when the Accumulation/Distribution Line forms a positive divergence. Be wary of weak positive divergences that fail to make higher reaction highs. A two-week positive divergence should be suspect. However, a multi-month positive divergence deserves serious attention.
The Accumulation/Distribution Line can also be used to confirm the strength or sustainability behind an advance. In a healthy advance, the Accumulation/Distribution Line should remain up or at least move in an uptrend. If the stock is moving up at a rapid pace, but the Accumulation/Distribution Line has trouble making higher highs or starts going sideways, buying pressure is relatively weak.
The Accumulation/Distribution Line can at time have problems detecting subtle changes in volume flows. The rate of change in a downtrend could be slowing, but it may be impossible to detect until the Accumulation/Distribution Line turns up. This drawback has been addressed in the form of the Chaikin Oscillator or Chaikin Money Flow.