" RoE is a seriously misleading measure of profitability. For businesses that are not very capital-intensive – such as asset management, or other professional service firms such as accountants – high returns on equity are achievable because the capital requirement is so small. Capital-intensive businesses – in the modern economy they are principally banks, utilities and resource companies – can achieve high returns on equity only through extreme leverage, as Deutsche Bank did. "

― , Other People's Money: The Real Business of Finance