Macro Subtotal Please Help!

I have a spreadsheet that has columns for "Side","Stock","No.of Shares","Price" and "Ave.Price"
It is formatted using a macro.

I need macro code that will group all trades by stock. For any changes in stock, function is sum, add subtotal to no.of shares and extension.Then add another subtotal, For
any changes in price, function is sum,add subtotal to no.of shares and extension.Extension is not
included in the columns but I would like to automate to add another field "Extension" right beside "Price". To compute for the values of Extension-No.ofShares*Price.


Can anyone help please?

See attached file