10.51 Williams Accumulation/Distribution ¶

The Williams Accumulation/Distribution index by Larry Williams forms a running total of “buying pressure” on up days, or “selling pressure” on down days.

                   / (close - true low)   if close > prev close
WAD = WAD[prev] + |  0                    if close = prev close
                   \ (close - true high)  if close > prev close

Buying pressure is represented by how far the close is above the true low (which is the lesser of today’s low or yesterday’s close). Selling pressure is represented by how far the close is below the true high (which is the greater of today’s high or yesterday’s close). Notice the difference “close - true high” is negative, so on down days WAD decreases.

The starting point (ie. the zero point) for the running total is arbitrary. In Chart it’s merely the segment of data first displayed.