A slide in commodity prices turns into a rout: GLD -3.2%, SLV -4.2%, USO -3%, Copper (JJC) -2.2%. At $1,506/oz., gold is threatening a $1,400 handle for the first time in nearly 2 years. After an early bounce, stocks move to session lows, the S&P 500 -0.7%. The long bond gains three-quarters of a full point, its yield down to a 2013 low of 2.93%. Update at 11:05: Now off 4.3%, gold slips below $1,500.