shows the time series plot of log(pt/pt−1).Its histogramis shown in Fig. 2. Figs. 1 and 2 suggested that GARCH models are applicable [18,19]. Some results based on GARCH models are summarized in Table 1. The means and standard deviations of logpt/pt−1 are presented in Table 2. In this article, we investigate the normality assumption of log(pt/pt−1) more closely and perform further nonparametric analysis on testing the day of the week effect over a longer period of time on the Shenzhen Stock Market. In examining the normality, we