Net worth: $45.3 billion

Age: 72

Country: US

Industry: Tech

Source of wealth: Self-made; Oracle

In 1977, Larry Ellison teamed up with two colleagues from an electronics company to start their own programming firm, which landed a contract not long after to build a relational database-management system for the CIA under the project code Oracle. The project grew into what is known today as Oracle Corp., which produced $37 billion in revenue last year. In 2010, Ellison reduced his annual salary from $1 million to $1, but he still takes in more than $60 million in total compensation thanks to generous stock awards. Ellison stepped down as CEO in 2014 after 38 years on the job and took on the role of chief technology officer.

The tech tycoon is also a generous philanthropist through partnerships with wildlife conservation groups and the Lawrence Ellison Foundation, which supports organizations that research aging and global infectious diseases. He's also a member of Bill Gates and Warren Buffett's Giving Pledge, committing to give away at least half of his fortune.

In the last year, Ellison's wealth has increased by $5.2 billion.