Sortino ratio

From Financial Literacy Wiki

Sortino ratio measures the risk-adjusted return of an investment asset, portfolio or strategy. It is a modification of the Sharpe ratio but penalizes only those returns falling below a user-specified target, or required rate of return, while the Sharpe ratio penalizes both upside and downside volatility equally, because it takes in the whole variance of portfolio.

It is thus seen as a more realistic measure of risk-adjusted returns than the Sharpe ratio.