The Day of the Week Effect Patterns on Stock Market Return and Volatility: Evidence for the Athens Stock Exchange

This paper investigates the day of the week effect in the Athens Stock Exchange (ASE) General Index over a ten year period divided into two subperiods: 1995-2000 and 2001-2004. Five major indices are also considered: Banking, Insurance, and Miscellaneous for the first subperiod, and FTSE-20 and FTSE-40 for the second subperiod. Using a conditional variance framework, which extends previous work on the Greek stock market, we test for possible existence of day of the week variation in both return and volatility equations. When using the GARCH (1,1) specification only for the return equation and the Modified-GARCH (1,1) specification for both the return and volatility equations, findings indicate that the day of the week effect is present for the examined indices of the emerging ASE over the period 1995-2000. However, this stock market anomaly seems to loose its strength and significance in the ASE over the period 2001-2004, which might be due to the Greek entry to the Euro-Zone and the market upgrade to the developed.