how to summarize net number of stocks traded (buy and sell)

I want to summarize net number of stocks traded by each trader. How to use VBA to do so? How to deal with buy and sell to get the net number? A sample is attached.

Thanks

Try a SUMPRODUCT formula to calculate the difference between the sum of sold and sum of bought.

In cell H27 of your sample workbook:

=SUMPRODUCT(--($F$1:$F$15="S"),--($H$1:$H$15=$G27),($G$1:$G$15))-SUMPRODUCT(--($F$1:$F$15="B"),--($H$1:$H$15=$G27),($G$1:$G$15))

Thanks Palmetto.