Running Total by Category with Compound Interest. List.Accumulate/Generate

Hi androo235 ,
this function calculates the compound interest:

( RTColumnName as text, MyTable as table, ValueColumn as text, InterestColumn as text) =>
let
    Source = MyTable,
    BuffValues = Table.Buffer( MyTable ),
    RunningTotal = 
      List.Skip(
        List.Generate ( 
        () => [ RT = 0, ValueColumn), RowIndex = 0 ],
        each  [RowIndex] <= Table.RowCount(BuffValues),
        each  [ RT = ([RT] + Record.Field(BuffValues{[RowIndex]}, ValueColumn) )  * (1 + Record.Field(BuffValues{[RowIndex]}, InterestColumn)),
                RowIndex = [RowIndex] + 1 ],
        each  [RT] 
        )
      ),
    #"Combined Table + RT" = 
      Table.FromColumns( 
        Table.ToColumns( MyTable )   
           & { Value.ReplaceType( RunningTotal, type {Int64.Type} ) } , 
        Table.ColumnNames( MyTable ) & { RTColumnName } )
in
    #"Combined Table + RT"

also check the solution with "fnCompounding" in the file attached.