Diversification is widely viewed as the “only free lunch” of finance. Unbeknownst to the free lunch crowd, skewness is typically positive for individual stocks and negative for diversified portfolios and thus diversification is not free. This undesirable move from positive to negative...

The authors modeled the non-normal returns of multiple asset classes by using a multivariate truncated Lévy flight distribution and incorporating non-normal returns into the mean-conditional value at risk (M-CVaR) optimization framework. In a series of controlled optimizations, they found that...