In a CNBC interview on Friday, Nassim Taleb told investors that bonds "have no upside" and "have run their course." Taleb pointed to negative interest rates as reasons investors could no longer count on bonds as a traditional hedge against market sell-offs. Taleb suggested that to protect investment portfolios, stock investors should have a tail hedge to protect against systemic risks. Taleb is an adviser to Universa Investments, which runs tail-risk-hedge investment strategies and posted a 4,144% return in the first quarter. Visit Business Insider's homepage for more stories.