Standard & Poor’s

…United States the largest are Standard & Poor’s and Moody’s Investors Service), and they generally run from AAA to D. Bonds with ratings from AAA to BBB are regarded as “investment grade”—i.e., suitable for purchase by banks and other fiduciary institutions. Bonds with ratings below BBB are considered “junk,” or…

S&P Global (formerly Standard & Poor’s), which sponsors a number of other market indexes—and also operates one of the “Big Three” credit rating agencies—traces its roots to an investment information service begun in 1860 by Henry Varnum Poor. In 1941, Poor’s original company, Poor’s Publishing, merged with Standard…