factor timing?(discretionary bottom up)为啥没有？啥时候用factor timing

NO.PZ2019012201000030 问题如下 How many of the following statements about approaches to portfolio construction are correct? Statement 1: In principle, a systematic top-wn manager woulemphasize macro factors anfactor timing and woulhave concentrateportfolios Statement 2: Bottom-up managers first emphasize security-specific factors, wheretop-wn managers first emphasize macro factors. One Two None A is correct. 考点：Approaches to portfolio construction 解析：第一个表述是错误的，它错在系统化策略旨在降低非系统性风险，因此通过这种策略构建出来的组合往往分散化非常好。 scretionary不是从firm specific出发吗

NO.PZ2019012201000030 问题如下 How many of the following statements about approaches to portfolio construction are correct? Statement 1: In principle, a systematic top-wn manager woulemphasize macro factors anfactor timing and woulhave concentrateportfolios Statement 2: Bottom-up managers first emphasize security-specific factors, wheretop-wn managers first emphasize macro factors. One Two None A is correct. 考点：Approaches to portfolio construction 解析：第一个表述是错误的，它错在系统化策略旨在降低非系统性风险，因此通过这种策略构建出来的组合往往分散化非常好。 我记得在Asset Allocation里面学过，MVO算出的马科维茨有效前沿有个问题就是得到的portfolio经常是concentrate因此才有的后续的解决方法。那为啥这里第一个表述应该是策略构建出来的组合往往分散化非常好呢？

NO.PZ2019012201000030 问题如下 How many of the following statements about approaches to portfolio construction are correct? Statement 1: In principle, a systematic top-wn manager woulemphasize macro factors anfactor timing and woulhave concentrateportfolios Statement 2: Bottom-up managers first emphasize security-specific factors, wheretop-wn managers first emphasize macro factors. One Two None A is correct. 考点：Approaches to portfolio construction 解析：第一个表述是错误的，它错在系统化策略旨在降低非系统性风险，因此通过这种策略构建出来的组合往往分散化非常好。 老师请问，第一个表述是错误的，它错在系统化策略旨在降低非系统性风险，因此通过这种策略构建出来的组合往往分散化非常好。为何分散化会非常好呢？

NO.PZ2019012201000030