Morgan Stanley Traders Lost $390 Million in One Day in August

Morgan Stanley, the world's second- biggest securities firm, said its quantitative strategy traders lost $390 million during a single day in August as their computer models failed to account for ``widespread'' investor selling.The company's traders lost money on 14 days during the quarter ended Aug. 31, ``with the largest single-day trading loss being $390 million,'' the New York-based firm said in a quarterly regulatory filing today.Morgan Stanley said last month that the quantitative strategies group lost $480 million during the quarter after they were caught off-guard when other investors sold securities to reduce borrowings. The company disclosed today that daily trading losses during the quarter exceeded the firm's trading value-at- risk calculation on six days during the quarter.The filing with the U.S. Securities and Exchange Commission also shows that the firm's traders generated more than $100 million of trading revenue on about 19 days during the quarter.