%0 Journal Article %A Harry M. Markowitz %T The “two beta” trap %D 1984 %R 10.3905/jpm.1984.408976 %J The Journal of Portfolio Management %P 12-20 %V 11 %N 1 %U https://jpm.pm-research.com/content/iijpormgmt/11/1/12.full.pdf