The DAX is the German share index. As the most important share index in Germany, it represents the 40 largest companies on the German stock market. They are listed in the Prime Standard of the Frankfurt Stock Exchange.

The composition is reviewed quarterly in March and September. Companies are selected on the basis of their market capitalization, free float and trading volume. The DAX serves as a benchmark for the German stock market. Investors, analysts and investment managers can thus compare their performance with the average of the German market.

There are also other indices like the DAX, such as the MDAX or SDAX. The MDAX, for example, stands for DAX-Midcap and comprises 50 of the largest and highest-turnover companies that no longer make it into the DAX. They therefore have a mid-cap or medium market capitalization. In this sense, the SDAX comprises companies with a low market capitalization.