BY LINA KHAN In July, the public learned that Goldman Sachs and several other large banks have morphed into giant merchants of physical goods, routinely shipping oil, running power plants, and amassing stocks of metals so large that Coca Cola accused them of hoarding. It was a disconcerting moment, as regulators realized that firms so recently known for their explosive mortgage-backed securities also deal in goods that can literally explode. These activities mean that banks supplying credit to Read More …