单个证券与投资组合的比较 Comparing a Portfolio with an Individual Security e(r)%o E(r)% F F 单个证券 证券组合 Individual security Portfolio 12-812-8 单个证券与投资组合的比较 Comparing a Portfolio with an Individual Security F E(r)% 证券组合 Portfolio F E(r)% 单个证券 Individual Security