NYSE Amex Composite Index

DEFINITION of 'NYSE Amex Composite Index'

An index made up of stocks that represent the NYSE Amex equities market. The NYSE Amex Composite Index is a market capitalization-weighted index, so the weight of each stock depends on the price of the shares and how many are outstanding.

BREAKING DOWN 'NYSE Amex Composite Index'

The index is used to quickly judge the overall movement of the NYSE Amex equities market. It was previously known as the American Stock Exchange (Amex) Composite Index and can be found under the symbol XAX.

NYSE Euronext acquired the American Stock Exchange on October 1, 2008, and branded it as NYSE Alternext US, which was then changed to the NYSE Amex Equities in 2009. It is primarily an equity market for emerging growth companies.