Add subtotal for Account/stock

[is4kib]

Hi,
I would like to create a report that shows the details of each stock, but it should also shows subtotals per each account.
I am able to create the list of all the stock with their information, but I'm not able insert the subtotals by account.
Can someone tell how I can do that or send to me an example?
Thanks in advance.
Ale

Example of result table
Account1 stock1 value1
Account1 stock2 value2
Account1 stock3 value3
Total Account 1 sum (stock value)
Account2 stock4 value4
Account2 stock5 value5
Total Account2 sum (stock value)
Account3 stock6 value6
Account3 stock7 value7
Total Account3 sum (stock value)