The MSCI ACWI is the “All Country World Index” - providing the broadest measure for global stocks.
The MSCI ACWI tracks performance of stocks from all over the world - literally. It includes all markets and gives the broadest picture for how world stocks are performing.
Developed markets account for some 75% of total global output, so the MSCI ACWI includes many countries that are not necessarily palatable contributors to world growth.