I'm leaning portfilio theory and have got some questions. global minimum variance portfolio is defined as the leftmost point on the efficient frontier which suggest it is a all-bond portfolio if risk free bonds (i.e, gvt bonds) is included as selectable asset.
Would anyone please confirm that the global MVP is actuallay all-bond portfolio in this case?
If that is true, then it will contradict the power of diversification which states that there exists a diversified portfolio which has the same risk as bond but higher return. Could anyone please help clarify that?