"'Hey, the Dow was down five hundred points.'"

Graph of Dow Jones indices showing the Black Monday crash of October 1987
Public DomainGraph of Dow Jones indices showing the Black Monday crash of October 1987 - Credit: Edward
The Dow Jones Industrial Average (also known as the Dow Jones index, the Dow Jones, the Dow 30 or simply, the Dow) is a stock market index.

Stock market indices are mathematical measures of stock market performance.

The Dow index was created by the American businessman Charles Dow and his statistician collaborator Edward Jones in 1896. It indicates the trading performance of 30 large American publicly-owned companies during a specific trading period.