#4 – Will & Isolde Liebherr ($6.1 Billion)
Isolde and Will Liebherr are siblings. Together, they run Liebherr Group, an equipment manufacturer that is based out of Bulle, Switzerland. Their father, Hans Liebherr, played an instrumental part in reconstructing Germany after World War II. He was a revered industrialist during his time, creating appliances, hydraulic excavators, concrete mixers, and much more.
When he died in 1993, the company was passed onto his two children, Will and Isolde. The pair continued to grow the business that their father started, and it’s been said that they intend on giving the company to their children once they time is through. Today, Liebherr Group employs over 40,000 people.