Apple Inc was accused in a new lawsuit of securities fraud for concealing a slump in demand for iPhones, particularly in China, leading to a $74 billion one-day slide in its market value once the truth became known. The complaint filed on Tuesday seeks damages for investors who bought Apple stock in the two months before Chief Executive Tim Cook on Jan. 2 unexpectedly reduced Apple's quarterly revenue forecast as much as $9 billion, in part because of the intensifying U.S. trade w