http://www.zerohedge.com/news/2016-05-08/death-gold-market-why-one-analyst-thinks-run-london-gold-vaults-imminent

Analyst warns of London gold market breakdown

"The convention of trading unallocated gold has been based on a fractional reserve system. It works as long as gold buyers retain confidence that the banks could deliver physical gold if demanded, but our analysis suggests that they could not."