The Global Industry Classification Standard (GICS) was created in 1999 in a joint effort by Standard & Poor's (S&P) and Morgan Stanley Capital International (MSCI). Its purpose is to classify all possible businesses into specific categories. This categorization allows investors, analysts, and academics a simpler means for breaking down and analyzing industrial and economic trends across a broad variety of potential cross-sections.

The GICS is broken down into:

Companies are assigned to a single classification according to their primary business activity. The determination of exactly what constitutes a company?s "primary business" is determined by S&P, and the criteria taken into account are primary source of revenue, earnings analysis, and market perception. Currently, over 19,000 companies have been classified under the GICS.