It has a lot to do with the spiking US Dollar which is responding to a spike in treasury yields over the last few months.  That is if a rise from 1.0% to 1.5% can be considered a spike.  Still historic lows, from the viewpoint of our well-aged perspectives, lol. 

IMO metal prices will all come back once the markets realize that nothing structural has changed overnight.  Inflation is still tame so long as Central Banks are hellbent on keeping a lid on interest rates, at the low end with pinned to zero Fed Funds rates and at the long end with perpetual quantative easing (QE). They are even hinting that they will let inflation run over their target for quite a while. This is great since it created negative real rates.  Great for gold. They have no choice but to keep interest rates low given the growing mountain of debt that they can barely service at current super low rates. 

I would welcome any counterpoints.  I have an aweful lot of profits in the gold miners, recently shaved in half, so as confident as I am in future metal prices like gold I do occasionally wonder during months like this whether I am missing something and should instead get out of all commodity plays sooner than later.