Big banks like Bank of America (BAC) and JPMorgan Chase (JPM) were on alert Thursday, expecting that Moody's Investors Service imminently will announce long-awaited, sweeping downgrades of many of the world's biggest banks. Moody's has already said it will release the reviews, which include significant downgrades for banks, by the end of June. Reuters, News Corp.'s Sky News and others said ratings cuts would likely come Thursday. Moody's on Feb.