, you can expect prices to increase, and on days of decreasing
, you can expect prices to decrease. This goes with the idea of
the market being in-gear and out-of-gear. Both PVI and work in similar
fashions: Both are a running cumulative of values, which means you either
keep adding or subtracting price each day to the previous day`s
sum. In the case of PVI, if today`s is less than yesterday`s, don`t add
anything; if today`s is greater, then add today`s price .
For , add today`s price only if today`s is less than