Perhaps (buys-sells)/(buys+sells) (if buys+sells=0 then 0) in that period then. The idea is to compare the relative volume of buys and sells in a time window to see if the market is bullish or bearish during that period.
I just was thinking about how visually this shart will appear - as I can understand it will got positiv if buys greater than sells and negative otherwise. The value will not exceed +/-1.
But how this an be modified to be ale to visualize not only side of trade but also the absolute siginificance. I mean to tell whether there are only small sells or big. Can it be some how combine in this idea? Of course we always can have existing already absolute trades volume chart but I am just curious.
What is your opinion?
To show the absolute scale just don't divide by total volume, though I'm of the opinion that if you have a stacked bar chart for the trade volume then that will be obvious.