Define: Sharpe Ratio

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Definition: Sharpe Ratio

What is the dictionary definition of Sharpe Ratio?

Dictionary Definition

The Sharpe Ratio or Sharpe Index or Sharpe measure or reward-to-variability ratio is a measure of the excess return (or risk premium) per unit of deviation in an investment asset or a trading strategy, typically referred to as risk (and is a deviation risk measure), named after William Forsyth Sharpe.


Full Definition of Sharpe Ratio

The Sharpe Ratio is a simple measure of the risk-adjusted return of an asset or portfolio. Using the Sharpe Ratio investors can compare investment strategies or managers, taking into account the amount of risk exposure each has in relation to their returns. The Sharpe Ratio was developed by William Forsyth Sharpe in 1966. (Sharpe was awarded the Nobel Prize in Economics in 1990 for his development of CAPM.) Due to its simplicity and ease of calculation, the Sharpe Ratio is a tool all investors can use to gauge their risk-adjusted-performance. The Sharpe Ratio also can help investors make decisions about their portfolio allocation.

The Sharpe Ratio is calculated by dividing the difference between the average return for the portfolio and the risk-free rate of return by the standard deviation of returns for the portfolio. The formula for the Sharpe Ratio looks like:

S(x) = (Rx – Rf) / StdDev(x)

Where x = portfolio, Rx = average returns of portfolio, Rf = risk-free rate of return, and StdDev(x) = the standard deviation of returns for x.

The Sharpe Ratio provides some insight into the efficiency of the portfolio by showing the amount of return generated per unit of risk assumed. The higher the Sharpe Ratio the better relationship of reward to risk in the portfolio. Because the Sharpe Ratio takes volatility of a portfolio into account its use is helpful when comparing different investment strategies or managers. The Sharpe Ratio concludes that the strategy or manager exhibiting the highest return with the lowest amount of risk (as measured by standard deviation) would be the better choice.


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Modern Language Association (MLA):
Sharpe Ratio. Payroll & Accounting Heaven Ltd. April 05, 2020
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Sharpe Ratio. Payroll & Accounting Heaven Ltd. (accessed: April 05, 2020).
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Sharpe Ratio. Retrieved April 05, 2020, from website:

Definition Sources

Definitions for Sharpe Ratio are sourced/syndicated and enhanced from:

  • A Dictionary of Economics (Oxford Quick Reference)
  • Oxford Dictionary Of Accounting
  • Oxford Dictionary Of Business & Management

This glossary post was last updated: 23rd March, 2020