In this study, we examine the informativeness of credit rating announcements in terms of information timeliness and contents. Specifically, we investigate whether both rating changes and watchlists have information contents. If so, is such information released to the market on a timely basis? By nature of credit rating process, rating changes are preceded by rating reviews, implying that rating change announcements are more likely to be anticipated than watchlists news release. In addition, we make groups according to the credit risk profiles. Then, we analyze whether lower rated category shows more pronounced response to the up or down rating announcements. Our study extends to not only stock market but also bond market to check whether there is any structural difference between bond and stock market.