You have not given much detail but here goes.
use =MAX(your_formula,-100%) to limit the loss to -100%
use =MAX(your_formula, 0) to limit money values to 0 minimum

best wishes - good luck with investments
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"David Drennan" wrote in message
...
I use Excel to record my investments. I project numbers on the basis of
"If
the rate of change so far in this share continues for the rest of the
year,
what will be the year-end outcome?" My cell formulae work well, but . . .
(a) How do you restrict the answer cell from being worse than -100% (I
can't lose more than my original investment), and
(b) How do you prevent the £ or $ amount being less than zero?

For the life of me, I cannot find the answer in Excel Help. I have tried
using 'Solver' and 'Data Validation', but having entered the values I
want,
my instructions are then ignored.