Volume Rate of Change (VROC), is an important indicator of gauging an instrument’s volume changes. It mathematically resembles Price ROC but indicates the ROC of the security’s volume and not its closing price. The Volume ROC demonstrates the speed at which volume is shifting. This can turn out to be rather helpful as almost each essential chart formation, such as peaks, bottoms or breakouts, is followed by a sudden volume raise.VROC is most useful when analyzing a security’s ability to cross supports/resistances, trend changes and trend strengths and when analyzing formations like peaks and foundations. Volume rate of change indicator resembles price rate of change indicator, but it is blind to price movements.
Volume Rate of change is calculated by dividing the amount of volume changed in the last ‘n’ periods, by the volume ‘n’ periods ago.
VROC = (Volume today – Volume ‘n’ days ago) / Volume ‘n’ days ago
Positive values of VROC indicate that the present volume is higher than the volume ‘n’ days ago; and negative values vice versa. Positive values are indications that the current bullish/bearish trend is still strong, and negative values are indications of the weakening of existing trends.
where i can find a software which can draw volume charts(ROC)