“…An additional difficulty is that these parameters are not directly observable; they are defined by the underlying model and by many other factors. For example, it appears that the volatility depends on the sampling frequency and on the delay parameter in the model equation see, e.g., Luong and Dokuchaev (2016). In addition, there is no a unique comprehensive model for stock price evolution; for example, there are many models with stochastic equations for volatility, with jumps, with fractional noise, etc.…”