This indicator shows the amount, in terms of a percentage, that the volume is currently above or below the current volume average.
((Volume - volumeMA) / volume) * 100
Ways to use:
1) We could consider movements in price to be extremely strong when the volumeGain is above the upper limit line
i.e. the current volume is more than 50% higher than the current average volume
2) We could consider movements in price to be extremely weak when the volumeGain is below the lower limit line
i.e. the current volume is less than 50% lower than the current average volume