老师，请问书本377页第九题，文中从哪方面能得出concentrate risk exposure这个结论？不太明白？

老师，请问书本376页第三点题答案index that contains a large number of constituents will tend to create higher tracking error than one with fewer constituents.为什么这里数量越是多，tracking error 越是高？不是应该分散化效果越好，tracking error越低吗？这个数值有没有一个范围？在范围之内是有分散效果，超过了就没有？

老师，请问书本375页第二题，preference for low- beta (risk) stocks说明什么？是large cap吗？能反映是什么风格的吗？

老师，请问书本332页第七题答案Note 5 is incorrect because the predictability of correlations is uncertain怎么来解释？Note5错在哪里？

revers mvo中正反两个方向的限制条件有什么具体区别

老师，请问书本332页第二题the fund has a style classified as aggressive这点能说明是什么风格？

老师，能否详细解释一下书本151页，第十三题答案是什么意思？This results from the fact that the factors typically represent what is referred to as a zero (dollar) investment or self- financing investment, in which the underperforming attri-bute is sold short to finance an offsetting long position in the better- performing attribute. Constructing factors in this manner removes most market expo-sure from the factors (because of the offsetting short and long positions)不太理解？为什么会和zero investment，self-financial investment long/short 有关系？

老师，请问书本216页，第三题照答案的解题思路，三个答案都应该可以？这道题该怎么理解？

我以为regert bias是避免买了会跌就不买了…上课老师做的比较里也是说这个bias是怕后悔所以不做。

为什么题目中positive shift引起的yield change是一个负数？positive shift在前面提到的说明里不是non parallel increase in all yield嘛？