On Aug. 5, 2020, Dan Gilbert was worth an estimated $7.5 billion. On Aug. 20, he was worth $45 billion. Forbes released its annual World Billionaires List this week, noting 86% of the worldâs wealthiest people are richer than they were a year ago. The world now has 2,755 billionaires, 660 more than last year. 2020 was a good year to be a billionaire â and Michiganâs richest were no exception. Gilbert, co-founder of Quicken Loans/Rocket Companies and owner of the Cleveland Cavaliers, was the biggest winner. Most of the increase is credited to his company offering shares on the New York Stock Exchange for the first time in early August.