Developed by and named after Larry Williams, his Accumulation/Distribution indicator is a price change index, whereby the biggest price difference from today?s high or low, or yesterday?s closing price is subtracted from today?s closing price.

Concretely, if prices are rising, the True Low (i.e. daily low or yesterday?s closing price) is subtracted from today closing price. Conversely, if prices are falling, the True High (today?s high or yesterday?s closing price) is subtracted from today?s closing price. If today?s close is equal to yesterday?s close, then today?s Accumulation/Distribution is zero. The Williams? Accumulation/Distribution indicator is a cumulative total of these daily values.

The cumulative sum of these (possibly extended) price changes is the Williams? Accumulation/Distribution, a price index open in both directions with the starting value of zero. The Williams? Accumulation/Distribution indicator bases its calculations on the difference between the Close and True High and True Lows and does not consider volume in its calculations.

This indicator is described in more details in the Steve Achelis' book "Technical Analysis from A to Z".

Formula: