William F. Sharpe, in full William Forsyth Sharpe, (born June 16, 1934, Cambridge, Mass., U.S.), American economist who shared the Nobel Prize in Economic Sciences in 1990 with Harry M. Markowitz and Merton H. Miller. Their early work established financial economics as a separate field of study.
Sharpe received a Ph.D. in economics from the University of California, Los Angeles, in 1961. He was influenced by the theories of Markowitz, whom he met while working at the RAND Corporation (1957–61). Later, Sharpe taught economics at the University of Washington in Seattle (1961–68) and, from 1970 at Stanford University until he retired from teaching to head his own investment consulting firm, Sharpe-Russell Research (later William F. Sharpe Associates), in the 1980s. He returned to Stanford as professor of finance in 1993, becoming emeritus in 1999. In 1996 Sharpe created the portfolio advising company Financial Engines, Inc.
Sharpe received the Nobel Prize for his "capital asset pricing model," a financial model that explains how securities prices reflect potential risks and returns. Sharpe's theory showed that the market pricing of risky assets enabled them to fit into an investor's portfolio because they could be combined with less-risky investments. His theories led to the concept of "beta," a measurement of portfolio risk. Investment analysts frequently use a beta coefficient to compare the risk of one stock against the risk of the broader stock market.