“As we study volume, we will find that quite frequently the negative implications are the ones from which we gain the most useful conclusions.”
—Harold M. Gartley
We have already discussed two methods of accumulating volume based on price. With the price accumulation volume indicators, you invert that process and accumulate price based on the actions of volume. Because price accumulation indicators are based on the magnitude of price change, small price moves have little effect. However, large price moves have a significant effect on price accumulation indicators.
Two of these indicators are known as the Positive Volume Index (PVI) and the Negative Volume Index ...