%0 Journal Article %A Keith P. Ambachtsheer %T The persistence of investment risk %D 1989 %R 10.3905/jpm.1989.409240 %J The Journal of Portfolio Management %P 69-71 %V 16 %N 1 %U https://jpm.pm-research.com/content/iijpormgmt/16/1/69.full.pdf