英文名称：Downgrade 中文名称：下调评级／降低信用评级指信用评级机构调降债务发行人或债务工具的信用等级。e.g. Deutsche Bank AG (DB) fell 4% premarket, under pressure from a falling market for U.K. and European bank stocks and following a downgrade by analysts at Morgan Stanley. Analysts called Deutsche Bank \"one of our least preferred wholesale banks in Europe.\" A negative change in the rating of a security. This situation occurs when analysts feel that the future prospects for the security have weakened from the orginal recommendation, usually due to a material and fundamental change in the company's operations, future outlook or industry. Analysts place recommendations on securities to give their clients or investors a general idea on the expected performance of that security looking forward. These recommendations are adjusted when the basis behind the recommendation changes, such as the price of the stock or newly released data in the company's financial statements. An analyst may downgrade a stock from a buy to a sell, after the company released information about an Securities and Exchange Commission investigation into the company's operations.