Sum to first negative number function

[oneandtwo]

Hello guys...

I have different numbers in a column. The problem is I would like to Sum sequence of numbers from C3 (as it is seen on a picture attached) to the first negative number in a column. In a picture of representantion the results should be 2, however I have to say numbers in column do change and so function should always calculate from up to the bottom.

So far I tried this function, but with no sucess, can any help me understand it better please?

Please Login or Register  to view this content.

PIC:

http://postimg.org/image/b2fhdqooj/

[Ron Coderre]

Try this in your sample data:

Please Login or Register  to view this content.

EDITED TO INCLUDE THIS COMMENT:
Based on your sample, I assumed that the only valid values are -1, 0, or 1.

Is that something you can work with?

[shg]

Confirmed with Ctrl+Shift+Enter:

=SUM(C2:INDEX(C2:C15, MATCH(TRUE, C2:C15<0, 0) - 1))

[oneandtwo]

Amazing Ron Coderre! Thank you very much!

[oneandtwo]

SHG, your formula works as well. Thank you as well!

[oneandtwo]

Yes, I have only threee signals: -1, 0 and 1. Thanks.