The DAX—also known as the Deutscher Aktien Index or the GER40—is a stock index that represents 40 of the largest and most liquid German companies that trade on the Frankfurt Exchange. The prices used to calculate the DAX Index come through Xetra, an electronic trading system. A free-float methodology is used to calculate the index weightings along with a measure of the average trading volume.

The DAX was created in 1988 with a starting index level of 1,163 points. DAX member companies represent roughly 75% of the aggregate market capitalization that trades on the Frankfurt Exchange.

The index was historically comprised of 30 companies but was expanded to 40 as of Sept. 3, 2021.

• The DAX is a German blue-chip stock market index that tracks the performance of the 40 largest companies trading on the Frankfurt Stock Exchange.
• Xetra is an electronic trading system that provides the prices used to calculate the DAX index.
• A few of the globally recognized companies on the DAX include Volkswagen, Bayer, BMW, and Adidas.