Positive Volume Index Strategy

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

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