Remove["Global`*"]
k=RandomFunction[GeometricBrownianMotionProcess[-0.00096,0.239317,3061.44],{0,5,1}];
s=k["Values"];
s[[5]]
Remove["Global`*"]
s[0]=3061.44;
r=-0.000960;
[Sigma]=0.239317;
[CapitalDelta]t=1;
s[u_]:=s[u-1]*Exp[(r-0.5*[Sigma]^2)*[CapitalDelta]t+Sqrt[[CapitalDelta]t]*[Sigma]*z[[u+1]]];
w=RandomFunction[WienerProcess[r,[Sigma]],{0,5,1}];
z=w["Values"];
s[5]
Remove["Global`*"]
s[0]=3061.44;
r=-0.00096;
[Sigma]=0.239317;
[CapitalDelta]t=1;
s[x_]:=s[x-1]*Exp[(r-0.5*[Sigma]^2)*[CapitalDelta]t+Sqrt[[CapitalDelta]t]*[Sigma]*InverseCDF[NormalDistribution[0,1],RandomReal[]]];
s[5]