Test it:
DECLARE @tmp TABLE (RowNo INT, Col1 INT)
INSERT INTO @tmp (RowNo, Col1)
VALUES(1, 614), (2, -187), (3, -5),
(4, -21), (5, -8), (6, -30)
SELECT t1.RowNo, t1.Col1, SUM(t2.Col1) AS CurrValue
FROM @tmp AS t1 INNER JOIN @tmp AS t2 ON t1.RowNo >= t2.RowNo
GROUP BY t1.RowNo, t1.Col1
ORDER BY t1.RowNo
Result:
RowNo Col1 CurrVal
1 614 614
2 -187 427
3 -5 422
4 -21 401
5 -8 393
6 -30 363