He is known as the ‘greatest investor of all time’ and he created the blueprint for today's investing strategies

Harry Max Markowitz

Diversify, he once responded when asked how investors should approach the stock market.

Harry Max Markowitz is an American economist who is best known for his pioneering work in modern portfolio theory, studying the effects of asset risk, return, correlation and diversification on probable investment portfolio returns. He's a recipient of the 1989 John von Neumann Theory Prize and the 1990 Nobel Memorial Prize in Economic Sciences.

When ranking the greatest investors of all time, many financial pundits put Markowitz at the top of their list because he is someone who constructed a process by which more people outperformed thanks to the lessons he provided.

Markowitz’s revolutionary work in modern portfolio theory decades ago has been credited with an investing sea change that resonates on Wall Street to this day.

Portfolio theory; sparse matrix methods; and simulation language programming (SIMSCRIPT). Sparse matrix methods are now widely used to solve very large systems of simultaneous equations whose coefficients are mostly zero.

SIMSCRIPT has been widely used to program computer simulations of manufacturing, transportation, and computer systems as well as war games. SIMSCRIPT included the Buddy memory allocation method, an algorithm that divides memory into partitions to try to satisfy a memory request as suitably as possible, which was also developed by Markowitz.

An economist by training, he technically wasn’t a professional investor at all. However, his trailblazing innovations made him legendary in the financial world.