Inverse Running Total

[Anonymous]

I am attempting to calculate an inverse running total on values. So I would in essence start with a value, 100, and in an indexed format reduce that value based on the next indexed field. 

Example: 

Index	Value	Running Difference
1	100	100
2	10	90
3	40	50
4	40	10
5	20	-10

[CNENFRNL · Accepted solution]

Running Diff = 
MINX( FILTER( INFO, INFO[Index] = 1 ), INFO[Value] )
    - SUMX(
        FILTER( INFO, 1 < INFO[Index] && INFO[Index] <= EARLIER( INFO[Index] ) ),
        INFO[Value]
    )

[Anonymous]

This solved my needs, thank you very much!