We will show that not any mean of the revenue rates of the industrial indexes is significantly beyond value zero at confident level 0 . 90 . moreover the mean of the revenue rate of sse 30 index is negative ( though not significant ) . and the fact of " the heritage of variance " appears congruous to the feature of industries represented by the corresponding indexes 第二章，通过分析上海股市各分类指数的收益率序列的特征，得出结论如下：各序列都非正态，有自相关性和异方差存在，相对适宜用garch ( 1 ， 1 )来拟合；除了上证商业( 1b0002 ) ，各分类指数收益率的均值在85的置信度下都不显著地异于0 ，而上证30 ( 1b0007 )的收益率竟小于0 ；在各分类指数中， ”波动继承性”的结果和各分类指数对应行业的特征是相关的。
