SQL Server 2022

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WITH Grps AS (
    SELECT V.YourID,
           V.YourValue,
           COUNT(CASE WHEN V.YourValue < 0 THEN 1 END) OVER (ORDER BY V.YourID ROWS UNBOUNDED PRECEDING) AS Grp
    FROM (VALUES(1,0),
                (2,1952),
                (3,0),
                (4,0),
                (5,0),
                (6,0),
                (7,0),
                (8,98),
                (9,-333),
                (10,98),
                (11,98),
                (12,98),
                (13,165),
                (14,113),
                (15,113),
                (16,113),
                (17,138),
                (18,65),
                (19,65),
                (20,115))V(YourID,YourValue)),
Sums AS(
    SELECT G.YourID,
           G.YourValue,
           G.Grp,
           SUM(G.YourValue) OVER (PARTITION BY G.Grp ORDER BY G.YourID ROWS UNBOUNDED PRECEDING) AS CumulativeSum
    FROM Grps G)
SELECT S.YourID,
       CASE WHEN LAG(S.CumulativeSum,1,S.CumulativeSum) OVER (PARTITION BY S.Grp ORDER BY S.YourID) < 0 THEN S.CumulativeSum ELSE S.YourValue END AS NewValue
FROM Sums S
ORDER BY S.YourID;

YourID	NewValue
1	0
2	1952
3	0
4	0
5	0
6	0
7	0
8	98
9	-333
10	-235
11	-137
12	-39
13	126
14	113
15	113
16	113
17	138
18	65
19	65
20	115

Warning: Null value is eliminated by an aggregate or other SET operation.