What Is the CAC 40?

The CAC 40 is the French stock market index that tracks the 40 largest French stocks based on the Euronext Paris market capitalization. The CAC 40 started with a base value of 1,000 in December 1987 and continued to operate on a total market capitalization system until 2003 when it was changed to a free float adjusted market capitalization methodology.

  • The CAC 40 is the benchmark equity index for public companies traded on the Euronext Paris.
  • The index is made up of the largest 40 companies listed in France screened by market capitalization, trading activity, size of balance sheet, and liquidity.
  • The multinational reach of the companies listed on the CAC 40 makes it the most popular European index for foreign investors. 

Understanding the CAC 40

CAC 40 stands for Cotation Assistée en Continu, which translates in English to "continuous assisted trading", and is used as a benchmark index for funds investing in the French stock market. The index also gives a general idea of the direction of the Euronext Paris, the largest stock exchange in France formerly known as the Paris Bourse. The CAC 40 represents a capitalization-weighted measure of the 40 most significant values among the 100 highest market caps on the exchange. The index is similar to the Dow Jones Industrial Average (DJIA) in that it is the most commonly used index that represents the overall level and direction of the market in France.

The CAC 40 index represents the 40 largest equities listed on the Euronext Paris in terms of liquidity, and includes such companies as L’Oreal, Renault, and Michelin.

An independent steering committee reviews the CAC 40 index composition quarterly. At each review date, the committee ranks companies listed on Euronext Paris according to free float market capitalization and share turnover in the previous year. Forty companies from the top 100 are chosen to enter the CAC 40, and If a company has more than one class of shares traded on the exchange, only the most actively traded of these will be accepted into the index.

Impact of CAC 40

The CAC 40 is one of the main national indices of the cross-border European stock exchange, Euronext. Euronext was created in 2000 from the merger of the Amsterdam, Brussels, and Paris stock exchanges. In 2007, Euronext completed their agreed merger with the New York Stock Exchange (NYSE) Group, resulting in the formation of NYSE Euronext.

Euronext manages a variety of exchanges located in six different countries. The company operates the world's most liquid exchange group, with nearly 4,000 listed companies, representing a total market capitalization of approximately $30.5 trillion.

Market capitalization refers to the total dollar market value of a company's outstanding shares. Commonly referred to as market cap, it is calculated by multiplying a company's shares outstanding by the current market price of one share. The investment community uses this figure to determine a company's size, as opposed to using sales or total asset figures. Given its simplicity and effectiveness for risk assessment, market capitalization can be a helpful metric in determining which stocks you are interested in, and how to diversify your portfolio with companies of different sizes.

Trading the CAC 40

A number of exchange-traded funds (ETFs) follow the CAC 40. Among them are:

  • Lyxor ETF CAC 40 (CAC)
  • EasyETF CAC 40 (E40)
  • Amundi ETF CAC 40 (C40)
  • DBXT CAC 40 (X40)
  • ComStage ETF CAC 40 (PC40)