Sharpe ratio
From Conservapedia
The Sharpe ratio or reward-to-variability ratio is a financial ratio that measures the compensation (called a "risk premium") an investor receives for bearing an additional unit of risk. It is defined as
where 
is the asset's expected return, 
is the risk-free rate (normally, the rate of return of a United States T-bill) and 
is the risk associated with the investment.
Development
The concept of a Sharpe ratio was first developed by William Sharpe, a professor of finance at Stanford University.
