The European Central Bank is tightening rules on officials’ personal investments after a scandal at the Federal Reserve over private transactions prompted similar moves there. Members of the ECB’s Governing Council and Supervisory Board will only be allowed to buy “publicly listed, broadly diversified” products such as exchange-traded and mutual funds, meaning they’re barred from investing in individual stocks and bonds of single countries. Officials will also be required to hold on to their investments for one year, compared with one month under previous regulations, the ECB said Friday in a statement. “The ... (full story)