Index

An index is a portfolio of stocks or bonds used to evaluate a sector, a theme or an economy according to criteria defined by the creator of the index.

In the case of a stock index, its value reflects the prices of all the shares that compose it - proportionally, equally weighted, etc. For example, the level of the CAC 40 index is determined from the prices of 40 shares selected from the 100 listed companies with the largest French market capitalizations.