Of the world's 500 largest stock-market-listed companies measured by revenue in 2019, the Fortune Global 500, 29 are headquartered in Germany. 30 major Germany-based companies are included in the DAX, the German stock market index which is operated by Frankfurt Stock Exchange. Well-known international brands include Mercedes-Benz, BMW, Volkswagen, Audi, Siemens, Allianz, Adidas, Porsche, Bosch and Deutsche Telekom. Berlin is a hub for startup companies and has become the leading location for venture capital funded firms in the European Union. Germany is recognised for its large portion of specialised small and medium enterprises, known as the "Mittelstand" model. These companies represent 48% global market leaders in their segments, labelled Hidden Champions.