The authors use a variance ratio test to test the weak form of market efficiency as regards capital markets in the Czech Republic, Slovakia, Hungary, Poland, and in the United States. Market efficiency was tested using weekly and monthly values of relevant market indices in a period from 1993...

Long-term memory processes have been extensively examined in recent literature as they provide simple way to test for predictabilty in the underlying process. However, most of the literature interprets the results of estimated Hurst exponent simply by its comparison to its asymptotic limit of...

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...