NEW YORK (CNNMoney) – Some of the world's biggest banks were downgraded Thursday by rating agency Moody's, which cited concerns about the stability of the global financial system. Moody's cut the ratings of 15 financial institutions after U.S. markets closed Thursday, including giants like Bank of America, Goldman Sachs and JPMorgan. "All of the banks … Continue reading Are we headed for double-dip recession? Christine Romans on what Moody's credit cut for 15 banks means for the economy