Over the past few years, the Value at Risk indicator (VaR) has evolved, without doubt, into the most frequently used comprehensive tool for assessment of potential losses caused by adverse changes in market rates. However, the common models used for VaR assessment are based only on mid prices...

Volatility of the financial time series belongs to the crucial estimated parameters in finance (e.g. in risk management, derivative pricing). It is well known, that volatility varies in time, so that new approaches of volatility modeling have appeared. In this paper two models of the conditional...