The MSCI World is a widely followed global stock market index that tracks the performance of around 1,500 large and mid-cap companies across 23 developed countries.
[1][2] It is maintained by MSCI, formerly Morgan Stanley Capital International, and is used as a common benchmark for global stock funds intended to represent a broad cross-section of global markets.
The index includes a collection of stocks of all the developed markets in the world, as defined by MSCI.
But because the index excludes stocks from emerging and frontier economies, it is less worldwide than the name suggests.
The index includes companies in the following countries/regions: The GICS breakdown is shown here, with information technology being the biggest sector.