Reward-Risk Ratios

We introduce three new families of reward-risk ratios, study their properties and compare them to existing examples. All ratios in the three families are monotonic and quasi-concave, which means that they prefer more to less and encourage diversification. Members of the second family are also scale invariant. The third family is a subset of the second one, and all its members only depend on the distribution of a return. In the second part of the paper we provide an overview of existing reward-risk ratios and discuss their properties. For instance, we show that, like the Sharpe ratio, every reward-deviation ratio violates the monotonicity property.