DAX is a trademark of ISS STOXX Index GmbH, which belongs to Deutsche Börse Group. The DAX index is both a barometer for the German economy and a benchmark for a large number of financial products. As a selection index, it tracks the largest companies listed on Frankfurter Wertpapierbörse (FWB®, the Frankfurt Stock Exchange). In addition to the DAX itself, the DAX index family comprises further indices such as the MDAX®, which tracks the 50 largest companies that follow DAX, the SDAX® index, with the 70 next biggest companies after the MDAX index, and TecDAX®, with a focus on technology companies.
The composition of the indices is reviewed quarterly. There is a clear and transparent
set of rules regarding admission and removal of companies to or from the indices (see Guide Equity Indices). As of September 2016, the process for selecting companies in all indices is purely quantitative as well as completely automated, and aligned with the existing DAX index rules.
These rules ensure that the indices maintain a high degree of tradability, replicability and continuity. The automated process leads to a further improvement in the transparency of the index rules and visibility of changes and enables an objective and fact-based process for determining the composition of the equity indices.
The indices are reviewed on the third trading day of the review month. Changes take effect on the Monday after the third Friday in the review month.