Harry Markowitz

Harry Markowitz published his seminal paper "Portfolio Selection" in the Journal of Finance in 1952, introducing the mathematical framework for portfolio diversification. His mean-variance framework showed that for a given level of return, risk can be minimized through diversification, and vice versa — giving rise to the concept of the efficient frontier. Markowitz received the Nobel Prize in Economics in 1990 along with Sharpe and Miller. His work became the foundation for institutional portfolio construction, index funds, and eventually factor investing. He passed away in 2023. His later contributions included extensions of the mean-variance framework to incorporate estimation error and parameter uncertainty, and he continued to publish research on portfolio optimization algorithms into his eighties, demonstrating an enduring engagement with the practical challenges of implementing his theoretical framework in real-world investment management contexts.