The largest exchange traded funds backed by physical holdings of silver are down almost 42% in 2013 following Thursday’s strong volume drubbings of nearly 4%. With Thursday’s close at $18.81, the iShares Silver Trust (NYSEArca: SLV) is just about 6% removed from its 52-week low. The $18 area represents silver’s July lows and the longer the metal labors below $20, the further removed it is from notching a legitimate technical breakout.