The Accumulation Distribution Line and On Balance Volume (OBV) are cumulative volume-based indicators that sometimes move in opposite directions because their basic formulas are different. Joe Granville developed On Balance Volume (OBV) as a cumulative measure of positive and negative volume flow. OBV adds a period’s total volume when the close is up and subtracts it when the close is down. A cumulative total of this positive and negative volume flow forms the OBV line. This line can then be compared with the price chart of the underlying security to look for divergences or confirmation.
As the formula above shows, Chaikin took a different approach by completely ignoring the change from one period to the next. Instead, the Accumulation Distribution Line focuses on the level of the close relative to the high-low range for a given period (day, week, month). With this formula, a security could gap down and close significantly lower, but the Accumulation Distribution Line would rise if the close were above the midpoint of the high-low range. The chart above shows Clorox (CLX) with a big gap down and a close near the top of the day’s high-low range. OBV moved sharply lower because the close was below the prior close. The Accumulation Distribution Line moved higher because the close was near the high of the day.