We study the effects of the first-ever ratings for corporate securities. In 1909, John Moody published a book that partitioned the majority of listed railroad bonds into letter-graded ratings based on his assessments of their credit risk. These ratings had no regulatory implications and were...

This article takes the defaulted bonds as the research object, uses the structural break points of bond prices as the benchmark, and the days of the largest rating downgrade or the first downgrade or negative rating outlook as the time of rating adjustment. The number of days between the two can...