A rational approach to investing is manifested through the realization of a higher yield for a given level of risk, and the realization of a given yield by accepting lower risk levels. Through the investment process, the question that is brought to investors’ attention is the importance of...

Using different techniques, models and strategies investors are trying to construct their own portfolio whose dynamic performance should beat the market, or portfolio that should achieve yields more than the yield of the market in equilibrium. Active search for undervalued stocks, as well as the...

For proper valuation of risk to which the portfolio of financial assets is exposed, it is necessary to forecast the second moments of financial time series, that is variabilities. The empirical investigations show that financia time series are heteroskedastic, i.e. their volatility is not...