Stefan Quandt (born 9 May 1966) is a German billionaire heir, engineer and industrialist. As of October 2021, his net worth is estimated at US$23.2 billion and ranked at number 89 on Bloomberg Billionaires Index. Early life Quandt was born in Bad Homburg to Herbert Quandt and Johanna Quandt. He earned a degree from the University of Karlsruhe where he studied economics and engineering, from 1987 to 1993. Career From 1993–1994, Quandt worked for the Boston Consulting Group in Munich. From 1994 to 1996 he worked for Datacard Group of Minneapolis as a marketing manager in Hong Kong. BMW On his father's death in 1982 Quandt inherited 17.4% of BMW, the company his father had saved from bankruptcy in 1959. From further purchases he later owned 23.7% of the company. Following his mother’s death in 2015, Quandt’s voting stake in BMW temporarily increased to 34.19 percent, above a 30 percent threshold which triggered a compulsory takeover offer under German rules. He subsequently asked the Federal Financial Supervisory Authority (BaFin) to be excused from these rules. In 2018, Quandt became BMW’s largest single shareholder when his direct ownership increased with shares inherited from his mother, giving him a so-called “blocking stake” of 25.83 percent, worth 13.4 billion euros ($16.6 billion). He currently serves BMW as a deputy chairman of the supervisory board. Delton Quandt also inherited from his father substantial holdings in other companies, many of which he has been running through his holding company, Delton AG, since 1989. These include: 76.8% of CEAG, (small power supplies and recharging devices for mobile phones) 87.6% of Logwin AG (formerly Thiel Logistik, a logistics and freight forwarding company) 100% of Biologische Heilmittel Heel GmbH, which makes homeopathic preparations 100% of CeDo Household Products, which makes freezer bags, plastic and aluminium wraps and foils, bin liners, and coffee filters With his mother, Quandt owned 18.3% of Gemplus International, a large digital security company, before its merger to form Gemalto in 2006. Aqton With a second holding company, Aqton SE, Quandt manages other investments, including in renewable energies: Heliatek, organic solar panels Solarwatt, manufacturer of PV panels, solar batteries and energy management solutions Kiwigrid, grid based renewable energy solution for utilities BHF, financial services Philanthropy Through the non-profit Aqtivator, Quandt supports projects for children, youth, and families with a focus on education, integration, and equal opportunity. Other activities Corporate boards Frankfurter Allgemeine Zeitung, Member of