Sharpe Ratio, Definition
Sharpe Ratio is a risk adjusted measure of a fund's market performance. It measures a fund's average historical return per unit of risk. The higher the number the better the fund has performed. This performance measure was developed by William F. Sharpe who won the nobel prize in Economics along with three other economists for their contributions to Modern Portfolio Theory.
See also: Sharpe Ratio Calculation from William F Sharpe, Sharpe Ratio Formula from MoneyChimp, Stock Market Discussion