The Global Industry Classification Standard (GICS) is an industry taxonomy developed in 1999 by MSCI and Standard & Poor's (S&P) for use by the global financial community. The GICS structure consists of 11 sectors, 25 industry groups, 74 industries and 163 sub-industries^[1] into which S&P has categorized all major public companies. The system is similar to ICB (Industry Classification Benchmark), a classification structure maintained by FTSE Group.

GICS is used as a basis for S&P and MSCI indexes used in the financial field which each company is assigned to a sub-industry, and to an industry, industry group, and sector, by its principal business activity. "GICS" is a registered trademark of McGraw Hill Financial and MSCI Inc.^[2][3]

The classification is as follows:^[1]

Per the MSCI World index, Information Technology is the biggest sector, with 22% of world capitalisation.

The classification standard is regularly updated by S&P Dow Jones Indices and MSCI. Numerous changes over the years have resulted in the addition, deletion, or redefinition of various sub-industries, industries, or industry groups.^[4] Since 1999, there have been two revisions at the sector level:

• In 2016, the real estate industry group (with the exception of mortgage REITs) was moved out of the financials sector to a newly created real estate sector.^[5]
• In 2018, the telecommunication services sector was renamed communication services. The sector was expanded to include media and entertainment companies previously in the consumer discretionary sector, as well as interactive media and services companies from the information technology sector.^[6]
• In March 2023, several revisions were made. ^[7]

• Industry Classification Benchmark
• International Standard Industrial Classification
• North American Industry Classification System
• Standard Industrial Classification
• Thomson Reuters Business Classification