Portfolios and Their Debt to an O.R. Nobel Winner
During WWII, academics developed “Operations Research” techniques involving statistics and linear programming to hunt enemy submarines, supply troops on the ground and deliver ordnance to targets. Soon after the war ended, Operations Research academics began to apply their methodologies to investing. In 1952 Harry Markowitz, a graduate student at the University of Chicago, published a paper on portfolio selection in the Journal of Finance. Markowitz’s quantitative approach to investment theory was radically different from the conventional stock market wisdom at the time, which focused on picking winning stocks and concentrating stock holdings to maximize return. Investors knew that holding stocks meant taking risks, and they were led to believe that the only way to reduce risk was to become more competent at picking stocks. Some investors were following the advice of Gerald M. Loeb, the co-founder of brokerage firm E.F. Hutton, who wrote “once you obtain competency, diversification is undesirable.” Markowitz’s work along with others gave birth to what is now known as Modern Portfolio Theory (MPT). MPT provided investors quantitative ways to reduce risk and optimize their return.