Data and econometric methodology
Our sample consists of 60 stocks from the FTSE-20 and FTSE-40 stock indices of the
Athens stock exchange. The dataset is grouped into the control and the derivatives
samples. The derivative group consists of the shares that are traded in the ADEX. The
control group consists of the shares of the abovementioned financial indices which are
not traded in the ADEX. As regards the volatility of share prices is modeled through
the ARCH (Engle, 1982) and the GARCH (Bollerslev, 1986) processes: