A turbulent financial environment may mean it's better to be in cash than fully invested in stocks, bonds and other assets, according to Mohamed El-Erian, chief economic advisor at Allianz.

"You cannot rely on correlations to be your main risk mitigator," he said at a news briefing Monday, referring to the strategy of investing in a diverse set of assets that are unlikely to all move lower simultaneously. "Cash remains a valuable thing to have in your strategic allocation."