Conclusion In this paper, we have introduced additional properties of the Diversification Ratio and of the Most Diversified Portfolio (MDP), and proposed a basic set of rules an unbiased, agnostic portfolio construction process should respect: the Portfolio invariance Properties. We find that the P adheres to these rules. using the MsCI world Index as a reference Furthermore, universe to compare the performance of the MDP with other approaches, we find that the MDP stands out, both in relative performance and exposure to Fama French factors. terms of classical financial theory defines the equity risk premium as the return of the un- diversifiable portfolio. In developing the MDP our goal was to articulate a theory and a consistent construction methodology that deliverer the full benefit of the equity risk premium to investors and their trustees, and we believe that our work shows that the MDP is a strong candidate for being the un-diversifiable portfolio.