Global Minimum-Variance Portfolios When Bonds Are Included

Summary

The document raises a portfolio-theory question about whether including government bonds as an available asset makes the global minimum-variance portfolio an all-bond allocation. It connects this question to the efficient frontier: the global minimum-variance portfolio is the point with the lowest variance among feasible portfolios, but the questioner infers that it must therefore be the bond-only choice when bonds are treated as risk-free.

It also asks whether that conclusion conflicts with diversification arguments suggesting that a mixed portfolio might offer higher returns at the same risk as bonds. No answer, model assumptions, data, or calculations are supplied, so the text does not establish that the minimum-variance allocation is all bonds or resolve the apparent contradiction. The issue depends on how risk-free borrowing and lending, asset returns, and portfolio constraints are represented. The useful takeaway is to distinguish the minimum-variance objective from claims about higher returns at a given risk, which involve the full feasible set and assumptions.

Key ideas

• The global minimum-variance portfolio minimizes variance over the feasible asset allocations.
• The document asks whether adding government bonds makes the minimum-variance portfolio bond-only.
• It contrasts minimum-variance selection with diversification claims about returns at equal risk.
• The question cannot be resolved from the document because it provides no assumptions or supporting analysis.

Tags

# global minimum variance portfolio vs all-bond portfolio


# global minimum variance portfolio vs all-bond portfolio












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?

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