Mis-placed brackets in formula?

[horseguards]

My first post. Nice to be here.

This is a formula in a cell (part of the financial derivatives formula, Black-76): which returns the value, 0.81:

=stk*EXP(-rt*(C6))*NORMSDIST(-C19)-C3*NORMSDIST(-(LN(C3/stk)+(rt+(C11^2)/2)*(C6))/(C11*SQRT(C6))) The reference to cell C19 above is the concern. This is the formula in cell C19 (it returns the valeue, 0.63): =(LN(ug/stk)+(rt+(C11^2)/2)*(C6))/(C11*SQRT(C6))-C11*(C6)^0.5 If I insert the formula from C19 into the first line , this is the result: =stk*EXP(-rt*(C6))*NORMSDIST(-(LN(ug/stk)+(rt+(C11^2)/2)*(C6))/(C11*SQRT(C6))-C11*(C6)^0.5)-C3*NORMSDIST(-(LN(C3/stk)+(rt+(C11^2)/2)*(C6))/(C11*SQRT(C6))) It returns the value, 2.4 rather than 0.18 (the desired answer). If I enter the numeric value from C19 (0.63) into the first formula, the result is correct (0.81). I suspect - though I may be wrong - the problem is with brackets. I am using Excel 97. Any suggestions greatly appreciated. Thank you.

 

[KRice]

If I'm not mistaken, you need one extra set of parentheses here (in red):
=stk*EXP(-rt*(C6))*NORMSDIST(- ( (LN(ug/stk)+(rt+(C11^2)/2)*(C6))/(C11*SQRT(C6))-C11*(C6)^0.5 ) )-C3*NORMSDIST(-(LN(C3/stk)+(rt+(C11^2)/2)*(C6))/(C11*SQRT(C6)))

 

[horseguards]

Well Kirk, you've done it. I hope I can repay in kind in due course.

Excel's syntax/order of precedence has always been a pain.

Thank you so much.

(I couldn't install XL2BB. Will try again.)

Grant.

 

[KRice]

You're welcome...I'm happy to help. If you are interested in eliminating some of the parentheses and tightening up the formula, give this a try:

=stk/EXP(rt*C6)*NORMSDIST(SQRT(C6)/C11*(C11^2/2-rt-LN(ug/stk)/C6))-C3*NORMSDIST(-SQRT(C6)/C11*(C11^2/2+rt+LN(C3/stk)/C6))