So I have been trying to implement a simple Heston calibration using crude MC with 10k scenarios and 1000 time steps and the best I could get is 3x of the observed implied volatility.
I suspect it has something to do with the way my initial guess worked, and therefore, I am just wondering:
Is the initial guess very critical (that a not-so-great initial guess could give you 3x the differences)
If it is, how can I get a good initial guess?