"It is a terrible mistake for investors with long-term horizons – among them, pension funds, college endowments and savings-minded individuals — to measure their investment 'risk' by their portfolio's ratio of bonds to stocks. Often, high-grade bonds in an investment portfolio increase its risk."
he also had this interesting observation in relation to bonds, obviousy not a fan of investing in bonds. Maybe he is warning investors of what will happen to bonds especially now after a historically low interest rate period as interest rates rise again.