RT Journal Article SR Electronic T1 The Symmetric Downside-Risk Sharpe Ratio JF The Journal of Portfolio Management FD Institutional Investor Journals SP 108 OP 122 DO 10.3905/jpm.2005.599515 VO 32 IS 1 A1 William T. Ziemba YR 2005 UL https://pm-research.com/content/32/1/108.abstract AB The Sharpe ratio, a most useful measure of investment performance, has the disadvantage that it is based on mean-variance theory and thus is valid basically only for quadratic preferences or normal distributions. Hence skewed investment returns can engender misleading conclusions. This is especially true for superior investors with a number of high returns. Many of these superior investors use capital growth wagering ideas to implement their strategies, which means higher growth rates but also higher variability of wealth. A simple modification of the Sharpe ratio to assume that the upside deviation is identical to the downside risk gives more realistic results.