Dunno, was just a theory I've seen that may fit. Not my theory personally but it's worth considering. All the gold being amassed in a certain place (where that is exactly is up for speculation...my guess is China....but it would have to be a global bank of some sort, not solely a Chinese bank) is for backing global currencies from a central location, including the dollar. A global gold standard.
Btw, no one said manipulation. If the theory is correct then movements now would be the most organic they've been in a long time.