Dan Gilbert cofounded what would become Quicken Loans, the largest mortgage lender in the U.S., in 1985 at 22 years old. Quicken, which originated $320 billion in mortgages in 2020, went public as Rocket Companies in August 2020 at a $36 billion valuation. He also owns the NBA’s Cleveland Cavaliers. He and his companies have invested $5.6 billion to purchase and rehab a swath of buildings in downtown Detroit, with a plan to create 24,000 jobs. He also cofounded online sneaker sale platform StockX, which became a unicorn in June 2019 and is now valued at $3.8 billion.