Summarize a measure values

I don't know your model, so I had to write such a mesaure in a model that I imagine there should be. A correct model.

// Your formula is incorrect for several reasons.
// One of them is that such a measure must return
// a number, not text. Also, your model needs to 
// be correct (think: star schema) to carry out
// correct and fast calculations.

ATM Balance =
var LastDateInContext = MAX( 'Dates'[Date] )
var Result =
    SUMX(
        DISTINCT( ATM[AtmID] ),
        // For each atm you should get the latest
        // amount in the current context, assuming
        // that 'Dates'[Date] is the column that
        // joins to your fact table (NetDailyTransactions)
        // on some NetDailyTransactions[Date] field.
        // I assume that the fact table
        // stores the net amount found in each atm
        // for any days where there were withdrawals
        // or fill-ups. Let's assume that the field
        // NetDailyTransactions[NetAmount] stores the
        // amount in the atm in question as recorded
        // at the end of such a day.
        MAXX(
            TOPN(1,
                CALCULATETABLE(
                    NetDailyTransactions,
                    // 'Dates' must be a proper date table
                    // in the model. See dax.guide/dateadd
                    // for guidance on how to build such
                    // a table.
                    'Dates'[Date] <= LastDateInContext,
                    ALLEXCEPT( NetDailyTransactions, ATM )
                ),
                NetDailyTransactions[Date],
                DESC
            ),
            NetDailyTransactions[NetAmount]
        )
    )
return
    Result