NYSE Arca Major Market Index

The NYSE Arca Major Market Index (or XMI or MMI), previously the AMEX Major Market Index, is the American price-weighted stock market index made up of 20 Blue Chip industrial stocks of major U.S. corporations. Several of the stocks are also components of the Dow Jones Industrial Average (DJIA).

Source: Wikipedia — NYSE Arca Major Market Index (CC BY-SA 4.0)