Washington’s Blog 
Dec 23, 2012
Big banks pledged the same mortgage to numerous people .
Similarly, big bullion banks borrow gold from central banks, and then rehypothecate it numerous times:
(Options contracts on all commodities are similarly over-leveraged.)
A 1999 study by the International Monetary Fund found that 80 central banks lent out 15% of their official gold reserves .
Central banks now appear to have too little gold to meet their commitments .
And private banks are raiding allocated gold accounts .