Ankheroo
I wouldn't put so much energy into figuring out day to day changes in the POG. As a %, it's not that much. For every long position there is always an offsetting short position. Traders can be long oil, silver, platinum, financials or whatever against offsetting short positions in gold.
Because of the very small amount of money as a % of the value of a contract, traders, especially retail, almost always use stop-loss orders. Traders on the floor talk to each other & become aware of a price that will touch off numerous stop-loss orders. The result are these violent price drops & sometimes rises in the price. These are a great source of income for floor traders but mean very little in the big picture. Don't sweat it.
Regards
Joltin