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Also known as the Big Board or The Exchange. N.Y.S.E. composite index. Composite index covering price movements of all new world common stocks listed on the New York Stock Exchange. It is based on the close of the market on December 31, 1965 at a level of 50.00, and is weighted according to the number of shares listed for each issue. Print changes in the index are converted to dollars and cents so as to provide a meaningful measure of changes in the average price of listed stocks. The composite index is supplemented by separate indices for four industry groups: industrial, transportation, utility, and finance.

See more at Wikipedia.org...

Also known as the Big Board or The Exchange. N.Y.S.E. composite index. Composite index covering price movements of all new world common stocks listed on the New York Stock Exchange. It is based on the close of the market on December 31, 1965 at a level of 50.00, and is weighted according to the number of shares listed for each issue. Print changes in the index are converted to dollars and cents so as to provide a meaningful measure of changes in the average price of listed stocks. The composite index is supplemented by separate indices for four industry groups: industrial, transportation, utility, and finance.