I have the following table

Col A Col B Col C
25-Aug-13 100 ALPHA
25-Aug-13 100 BETA
25-Aug-13 100 ALPHA
25-Aug-13 100 BETA
25-Aug-13 100 ALPHA
26-Aug-13 100 BETA
26-Aug-13 100 ALPHA
28-Aug-13 100 BETA
28-Aug-13 100 ALPHA

I wanted to use a SUMIFS formula to create a running total of the balance per Col C and Col A being equal to or lower than Col A (current row). Col B is the value being added together.

So far I have tried the following but neither are working:

=SUMIFS(B:B,C:C,C2,A:A,"<="A2)

=SUMIFS(B:B,C:C,C2,A:A,"<=(A2)")

I would be very grateful for any advice on how I can create this required formula,

Many thanks in advance!