It's not like they'd sell to one person for a set amount, as you sell (ie increase supply) and demand dwindles you have to lower your price.
That is the point. Unload it all in one quick dump at current market price ~$1350/oz.
.... the huge influx of supply drops the price like a rock. Buy up a ****load in one quick buy at new low price. Price skyrockets again because of the lack of supply..... repeat.
You (the USA) would control enough of this asset to artificial change the price on a whim.... since they know the buy and/or sell is coming, they're always going to be on the winning end of it since their actions cause the drastic reaction.