课件里面引用了原版书的一句话：
Higher active risk tend to have higher active share, this is not always the case.
这句话是不是说反了，我认为应该是higher active shares tend to have higher active risk, but this is not always the case. 当表里不一的时候，higher active shares 和 lower active risk共存。
按照课件里面引用的话，higher active risk 与lower active share无法共存，那higher active risk tend to have higher active shar，this is always the case.
