VBA Code - was bedeutet die K-Schleife?

Function stochvol(Expry, Strike, IntRate, SMax, SigMax, dt)
Dim ds, dsig, a, b, c, d, rho, DeltaS, DeltaSig, DeltaSig1, DeltaSig2, GammaS, GammaSig, XGamma, _
Theta As Double
Dim N, i, j, k As Integer
ds = Strike / SMax * 2
dsig = 1 / SigMax
N = Int(Expry / dt) + 1
dt = Expry / N
a = 0.2
b = 1
c = 1
d = 1
rho = 0
ReDim S(0 To SMax) As Double
ReDim Sig(0 To SigMax) As Double
ReDim VOld(-1 To SMax, -1 To SigMax) As Double
ReDim VNew(-1 To SMax, -1 To SigMax) As Double
For i = 0 To SMax
S(i) = ds * i
Next i
For j = 0 To SigMax
Sig(j) = dsig * j
Next j
For i = 0 To SMax
For j = 0 To SigMax
VOld(i, j) = Application.Max(S(i) - Strike, 0)
Next j
Next i
For k = 1 To N        'Hier die K-Schleife, die ich nicht ganz verstehe
For i = 0 To SMax - 1
For j = 0 To SigMax - 1
DeltaS = (VOld(i + 1, j) - VOld(i - 1, j)) / 2 / ds
DeltaSig1 = (VOld(i, j + 1) - VOld(i, j)) / dsig
DeltaSig2 = (VOld(i, j) - VOld(i, j - 1)) / dsig
DeltaSig = DeltaSig1
If (a - b * Sig(j))