The heart of Markowitz’s research was grounded in the basic relationship between risk and rewardHarry M. Markowitz, an economist who launched a revolution in finance, upending traditional thinking about buying stocks, died Thursday in San Diego. He was 95. Markowitz won the Nobel Memorial Prize in Economic Sciences in 1990 for his breakthrough research in stock market investments, what became known as ‘modern portfolio theory’, widely referred to as MPT. The death, at a hospital, was caused by pneumonia and sepsis, Mary McDonald, a longtime assistant to Markowitz, said, the New York Times (NYT) reported. In 1952, he published his...