Before revision:  The empirical results supports the AMH of Lo (2004 , 2005) for data of the more quali?ed stock market in Japan.
After revision:  The empirical results show that (1) market efficiency changes over time in the TOPIX and TSE2, (2) the market efficiency of the TSE2 is lower than that of the TOPIX in most periods, and (3) the market efficiency of the TOPIX has evolved since the bursting of the bubble economy in the early 1990s, but that of the TSE2 has not. Therefore, we conclude that the empirical results support Lo's (2004 , 2005) for data of the more quali?ed stock market in Japan.