Changes to the composition of an index

Indices reflect the development of a sector or a market. Their composition is therefore regularly adjusted to current developments within the reference area. For example, shares whose market capitalization has increased on the basis of free float are included in an index; other companies are removed from the index. Extraordinary events such as delisting, settlement, bankruptcy, and new listings also lead to an exchange of stocks in an index.
 
Changes to the composition of the DAX® are only made as scheduled in September, and additionally in March for the MDAX® and TecDAX®. The composition of the SDAX® can change on each chaining date, i.e. in March, June, September and December.
 
In addition, a company can be removed from the index outside the regular review dates if its market capitalization is no longer one of the 45 largest companies, or included if its market capitalization is one of the 25 largest companies. An exchange will then take place on the next chaining date.