HomeLearnGlossaryAmex Composite Index

What is the Amex Composite Index?

Amex Composite Index

The Amex Composite Index is an index made up of the equities quoted on the NYSE Amex market, formerly known as the American Stock Exchange, which is located in New York. It is not connected with the American Express financial services company, also sometimes abbreviated to Amex.

Key takeaways

  • The Amex Composite Index tracks equities on NYSE Amex market, formerly the American Stock Exchange, and is unrelated to American Express.

  • The index primarily covers smaller-cap stocks, exchange-traded funds, and derivatives, serving as an indicator of smaller-cap market health.

  • NYSE Amex handles approximately ten percent of US securities trading and weights the index by market capitalization.

  • The exchange has roots in the 19th Century and ended traditional face-to-face floor trading at the start of 2017.

Where have you heard about the Amex Composite Index?

As an investor, you may have heard it mentioned from time to time as an indicator of the health of the market for smaller-cap stocks. Investment guides may refer to it, as may the financial media.

What you need to know about the Amex Composite Index.

The Amex Composite Index comprises the shares listed on the NYSE Amex market, once a major competitor for the New York Stock Exchange, but now primarily a market for smaller-cap shares, exchange-traded funds and derivatives. About ten per cent of US securities trading is conducted through NYSE Amex. The index is weighted by market capitalisation. NYSE Amex, whose roots stretch back to the 19th Century, maintained traditional floor trading until very recently, announcing an end to face-to-face stock trading only at the start of 2017.