Question

Consider the following Excel worksheet:

   | A       B     C
 --+--------------------
 1 | company day  return
 --+--------------------
 2 | 1       1    2
 3 | 1       2    1
 4 | 1       3    1
 5 | 2       1    3
 6 | 2       2    2
 7 | 2       3    0
 8 | 3       1    1
 9 | 3       2    5
10 | 3       3    1

The worksheet is panel timeseries basically. In the example, it lists the stock returns for 3 companyies for 3 conseutive days. I now want to graph the total return (so: accumulated return for all companies) per day, as follows:

 return 8 |        * (C3+C6+C9=1+2+5=8)
        7 |
        6 |  * (C2+C5+C8=2+3+1=6)
        5 |
        4 |
        3 |
        2 |              * (C4+C7+C10=1+0+1=2)
        1 |
        0 +----------------------
             1     2     3    day

Is this possible to do in Excel and if so, how?

Answer 1

Setup a new chart graph on another sheet to group the data from your first larger chart into this format:

 --+--------------------
A1 | company1 company2 Company3
 --+--------------------
 1 | B2       C2    D2
 2 | B3       C3    D3
 3 | B4       C4    C4

Then, set the formula in cell B2 to something like = SUMIFS(C:C,A:A,A1,B:B,A2)
Where C:C, B:B and A:A reference the columns in the original graph and the A1 and A2 Reference the grouping chart.

Note that the SUMIFS formula is for Excel 2007 / 2010. I’ve included example worksheets for this method and using the same approach with an Array formula in older versions of excel.

Here is an example file for Excel version 2007 / 2010: https://dl.dropbox.com/u/19599049/GroupData_NewExcel.xlsx

Here is an example for old versions of excel:
https://dl.dropbox.com/u/19599049/GroupData_OldExcel.xls