Total return is the return on investing stocks or securities. It also refers to the dividend plus any capital gains or losses achieved by the stock or securities holder in the holding period.

'I hope the private sector will come in,' he said, but noted that there is currently a reluctance to buy mortgage securities because of the uncertainty around rights as a first-lien holder.

While China sold some holdings in June it retained its title as the largest holder of U.S. Treasury securities.