Construction group Hochtief joins Germany's blue-chip DAX index on Monday, replacing Porsche SE, the largest shareholder in Volkswagen, which drops to the mid-cap MDAX index.
The move marks the first time the Essen-based company has entered Germany's benchmark stock index and is particularly significant for index-tracking funds, which must adjust their portfolios to reflect the changes.
DAX membership is determined by strict criteria, including a company's free-float market capitalization and stock market trading volumes. Deutsche Börse reviews the composition of the DAX, MDAX, SDAX and TecDAX every three months.
Hochtief's promotion, announced in early June, follows a sharp rise in its share price over the past year. The company has benefited from strong demand for artificial intelligence-related data centres, particularly in the United States, as well as from large-scale infrastructure investment programmes and rising defence spending in many countries.
Its shares have more than tripled in value over the past 12 months.
With a market capitalization of around €38 billion ($43.5 billion), Hochtief qualified for inclusion in the DAX despite having a free float of only about 20%. The remaining 80% is owned by Spanish construction and infrastructure group ACS, which has controlled Hochtief since 2011.
Hochtief accounts for the majority of ACS's business activities. Around three-quarters of ACS's revenue in 2025 was generated by Hochtief companies.
The German group serves as the holding company for a global network of construction businesses involved in projects ranging from skyscrapers, hospitals, roads, bridges, tunnels and airports to solar parks, data centres, mining facilities and military infrastructure.
Most of Hochtief's business is generated through its international subsidiaries, including US-based Turner and Australian contractor Cimic. At the end of 2025, the group employed around 61,500 people worldwide, including about 3,700 in Germany.
