Maybe they don't have any?
Fed Should Sell Some Gold To Prevent ‘Run On The Bank’
Not maybe, they don't. The Fed only has a piece of paper or a "credit" to the gold at the Treasury (or so they say). And if you ask me, it's precisely for this reason.
Me thinks the Treasury flatten all the bars out and sold it all as Eagles to improve the Fed's cash flow. However, they ran out several years back and that is why they are buying gold on the open market to produce Eagles. Any wonder why they didn't mint any 2010-W UNC gold Eagles last year? Same for 2009. They had to sell the bullion versions but were buying the gold blanks from Australia to produce them.
I am not sure what the mint's markup is on the AGE but it is not nearly what it is on the W version. Another poor business decision.
When you have central bank that prints it's own money you can never really have a run where they run out of cash. We live in the digital age where the Treasury or Fed will step in before that happens and digitize the banks balances higher as the Fed will loan money to just about anyone....except it's citizens who are having a hard time getting credit from the banks that f'd us in the first place.