22. Diversification is more than “not putting all your eggs in one basket.” Good diversification seeks to add assets that are uncorrelated or negatively correlated with other assets in a portfolio. Uncorrelated assets still must be expected to earn more than one would expect to get by depositing cash in a checking account, to be worth risking money and inclusion in a portfolio. Moreover, uncorrelated assets do not deliver those returns in a synchronized fashion: they do not have to rise and fall at the same moment in time.

Mark Blyth, Austerity, loc. 715