Apparently one of the draft provisions coming out of the G20 calls for an increase of $500 billion in additional money for the IMF. That would be in addition to the $250 billion already pledged.
Some traders may have concluded that that would mean some dumping of gold somewhere down the line to raise the cash and are getting out of positions now before New York opens. I suppose Summers and the rest would like nothing better. Anyone's guess as to how the US Congress will vote on any gold sales this time around should that turn out to be the case.