Jose Luis Rubiralta

Jose Luis Rubiralta derives his fortune from Werfen, which he inherited from his late father Josep Maria Rubiralta, in 2012.

One of Spain's largest diagnostic companies, Werfen operates in 30 countries and employs 7,000 people.

The company traces its roots to his late father Josep Maria Rubiralta and uncle Francisco, who founded its predecessor Izasa in 1966.

Werfen's notable international acquisitions include Tem in Germany and Instrumentation Laboratory and Accriva Diagnostics in the U.S.

Rubiralta has been a member of the company's board since 2013. His brothers Jordi, Marc and Xavier, who are involved in the business, are also billionaires.