Clearly from time to time a gigantic seller wholly numb to self-interest steps up and slaps silver and gold with huge sales. ZeroHedge reports today that huge selling hit the European open, and at the US open $1.37 billion worth of gold was sold on the futures market. See the article at http://www.zerohedge.com/news/2014-07-14/gold-silver-plunge-most-2-months
This changes the price at the margin only and temporarily only. No manipulation can change the relentless primary uptrend, which is powered by relentless central bank money printing and relentless government spending. Attacks like this are not signs of strength, but of desperation.