如题追问 https://class.pzacademy.com/qa/157993
老师，补充一下原文信息：
- Kelly: I like to stress to clients that asset classes should have high within-group correlations but low correlations with other classes. In addition, because investors need to rebalance to a strategic asset allocation, asset classes need to have both sufficient liquidity and low transaction costs.
- Trainor: It is important that asset classes should be diversifying. I always look for low pairwise correlations with other asset classes.
就是想请问下Trainer说的 “low pairwise correlations” 和 Kelly 说的 “low correlations” 是有什么区别吗？pairwise correlation是什么东西？解析说这个pairwise correlation低并不代表correlation低是为什么？
