Friedman’s statistic S is asymptotically distributed as a χ2 with degrees of freedom k −1 under the null hypothesis that there was no the day of the week effect.We computed S using S-plus[25].The observed value of S was 32.64 (p < 0.0001). Hence,we would reject the null hypothesis by the Friedman test and conclude that there was a statistical significance to the day of the week effect for the log-transformed daily closing returns for the Shenzhen Stock Exchange during the period from December25,1995 to December31,2010