1. History
  2. Understanding the Post-Modern Portfolio Theory (PMPT)
  3. Components of the Post-Modern Portfolio Theory (PMPT) 


Post-Modern Portfolio Theory was introduced in 1991 by software entrepreneurs Brian M. Rom and Kathleen Ferguson to separate the portfolio-construction software developed by their company, Investment Technologies, LLC, from those handed by the traditional ultramodern portfolio proposition. It first appeared in the literature in 1993 in a composition by Rom and Ferguson in The Journal of Performance Measurement. It combines the theoretical exploration of numerous authors and has expanded over several decades as academics at universities in numerous countries tested these propositions to determine whether or not they had merit. The essential difference between PMPT and the ultramodern portfolio proposition of Markowitz and Sharpe (MPT) is that PMPT focuses on the return that must be earned on the means in a portfolio to meet some unborn pay-out. This internal rate of return (IRR) is the link between means and arrears. PMPT measures threat and price relative to this IRR while MPT ignores this IRR and measures threat as dissipation about the mean or average return. The result is mainly different portfolio constructions.  Empirical examinations began in 1981 at the Pension Research Institute (PRI) at San Francisco State University. Dr. Hal Forsey and Dr. Frank Sortino were trying to apply Peter Fishburn’s proposition published in 1977 to Pension Fund Management. The result was an asset allocation model that PRI certified Brian Rom to vend in 1988. Mr. Rom chased the term PMPT and began using it to request portfolio optimization and performance dimension software developed by his company. These systems were erected on the PRI strike threat algorithms. Sortino and Steven Satchell at Cambridge University co-authored the first book on PMPT.

Understanding the Post-Modern Portfolio Theory (PMPT)

The PMPT was conceived in 1991 when software contrivers BrianM. Rom and Kathleen Ferguson perceived there to be significant excrescencies and limitations with software grounded on the MPT and sought to separate the portfolio construction software developed by their company, Sponsor- Software SystemsInc. The proposition uses the standard divagation of negative returns as the measure of threat, while the ultramodern portfolio proposition uses the standard divagation of all returns as a measure of threat. After economist Harry Markowitz innovated the conception of MPT in 1952, latterly winning the Nobel Prize for Economics for his work centered on the establishment of a formal quantitative threat and return frame for making investment opinions, the MPT remained the primary academy of study on portfolio operation for numerous decades and it continues to be employed by fiscal directors.  Rom and Ferguson noted two important limitations of the MPT and its hypotheticals that the investment returns of all portfolios and securities can be directly represented by a common elliptical distribution, similar to the normal distribution, and that the friction of portfolio returns is the right measure of investment threat. Rom and Ferguson also meliorated and introduced their proposition of PMPT in a 1993 composition in The Journal of Performance Management. The PMPT has continued to evolve and expand as academics worldwide have tested these propositions and vindicated that they’ve merit. 

Components of the Post-Modern Portfolio Theory (PMPT) 

The differences in threat, as defined by the standard divagation of returns, between the PMPT and the MPT is the crucial factor in portfolio construction. The MPT assumes a symmetrical threat whereas the PMPT assumes an asymmetrical threat. strike threat is measured by target semi-deviation, nominated strike divagation, and captures what investors sweat most having negative returns.  The Sortino rate was the first new element introduced into the PMPT rubric by Rom and Ferguson, which was designed to replace MPT’s Sharpe rate as a measure of threat-acclimated return, and bettered upon its capability to rank investment results. Volatility skewness, which measures the rate of a distribution’s chance of total friction from returns above the mean to the returns below the mean, was the alternate portfolio-analysis statistic to be added to the PMPT rubric. Post-Modern Portfolio Theory (PMPT)vs. Modern Portfolio Theory (MPT) The MPT focuses on creating investment portfolios with means that are non-correlated; if one asset is negatively impacted in a portfolio, other means aren’t inescapably so. This is the idea behind diversification. For illustration, if an investor has oil painting stocks and technology stocks in their portfolio and new government regulation on oil painting companies hurts the gains of oil painting companies, their stocks will lose value; still the technology stocks will not be affected. The earnings in the tech stocks will neutralize the losses of the oil painting stocks.  The MPT is the primary system in which investment portfolios are constructed momentarily. The proposition is the base behind un-resistant investing. There are still, numerous investors that seek to increase their returns beyond what un-resistant investing can bring or reduce their threat in a more significant way; or both. This is known as seeking nascence; returns that beat the request, and is the idea behind laboriously managed portfolios, most frequently enforced by investment directors, particularly barricade finances. This is where the post-modern portfolio proposition comes into play, whereby portfolio directors seek to understand and incorporate negative returns in their portfolio computations.