[Tutor] Cumulative distribution function

[Michel Guirguis]

Good morning,

I have a problem with the cumulative distribution function in calculating derivatives. I am getting a call option figure of 2.5961 while it should be 2.9081. Could you please help.

 >>>S=50
>>> K=50
>>> r=0.03
>>> q=0.02
>>> sig=0.20
>>> T=0.5

>>> from math import*
>>> d1=(log(S/K)+(r-q+(sig*sig)*0.5)*T)/(sig*sqrt(T))
>>> d1
0.10606601717798211
>>> d2 =d1-sig*sqrt(T)
>>> d2
-0.03535533905932742
>>>  def cumdist():
call = 50*exp(-0.02*0.5)*cumdist*(d1)-50*exp(-0.03*0.5)*cumdist*(d2)

	
>>> call
2.596102990952506

Thanks,

Michel