Nassim Taleb warned investors that bonds "have no upside" and "have run their course" in an interview with CNBC on Friday. Taleb pointed to negative interest rates as reasons why investors can no longer count on bonds as a traditional hedge against market sell-offs. In order to protect your investment portfolio, Taleb suggested stock investors need to 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.