Gold miner exchange traded funds surged Thursday as precious metals prices climbed for the fourth session in a row on a weakening U.S. dollar. On Thursday, the VanEck Vectors Gold Miners ETF (NYSEArca: GDX) rose 6.5% and the VanEck Vectors Gold Junior Miners ETF (NYSEArca: GDXJ) gained 7.6% as the...