You have no proof there is or ever was 5B in the OS, in fact if there ever was that many shares in the OS we would have never seen the MM's having to print shares and throughout the fall of 2012 that is exactly what happened:
“The person who risks nothing, does nothing, has nothing, is nothing, and becomes nothing. He may avoid suffering and sorrow, but he simply cannot learn and feel and change and grow and love and live.”~Leo Buscaglia