19. Zhang Zhidong, cofounder of Tencent Holdings. Net worth: £11.6 billion ($15.8 billion). Also known as Tony Zhang, he was CTO of Chinese giant Tencent until 2014.
18. William Ding, founder and CEO of NetEase. Net worth: £12.9 billion ($17.5 billion). Ding founded NetEase in 1997 and it is now one of the world's biggest mobile games businesses.
17. Laurene Powell Jobs, widow of Steve Jobs. Net worth: £13.9 billion ($18.9 billion). She founded social impact enterprise Emerson Collective and was recently rumoured to be in talks to back BuzzFeed’s news division.
16. Azim Premji, chairman of Wipro Limited. Net worth: £13.9 billion ($18.9 billion). Premji is known as the czar of the Indian IT industry.
15. Elon Musk, CEO of Tesla and SpaceX. Net worth: £14.7 billion ($20 billion). Musk also runs tunnel infrastructure firm The Boring Company.
14. Paul Allen, cofounder of Microsoft. Net worth: £16.1 billion ($21.9 billion). As well as setting up Microsoft with Bill Gates, Allen is owner of NFL's Seattle Seahawks.
13. Lee Kun-Hee, chairman of Samsung Group. Net worth: £16.6 billion ($22.5 billion). He is the third son of Samsung founder Lee Byung-chul.
12. Michael Dell, founder and CEO of Dell Technologies. Net worth: £16.8 billion ($22.8 billion). Dell is the world's largest privately held technology company.
11. Masayoshi Son, founder and CEO of SoftBank. Net worth: £16.8 billion ($22.8 billion). SoftBank has a huge $100 billion tech investment fund.
10. Steve Ballmer, former Microsoft CEO. Net worth: £28.4 billion ($38.5 billion). Ballmer now owns NBA's Los Angeles Clippers.
9. Jack Ma, executive chairman of Alibaba Group. Net worth: £28.9 billion ($39.2 billion). Alibaba is China's biggest e-commerce company.
8. Pony Ma Huateng, CEO of Tencent. Net worth: £33.6 billion ($45.6 billion). Ma is now China's richest man.
7. Sergey Brin, cofounder of Google. Net worth: £34.8 billion ($47.2 billion). He is president of Google's parent company, Alphabet.
6. Larry Page, cofounder of Google. Net worth: £35.2 billion ($47.8 billion). Page was Google's first CEO until 2001.
5. Larry Ellison, executive chairman of Oracle. Net worth: £43.3 billion ($58.8 billion). Ellison cofounded Oracle in 1977 and still works as the firm's CTO.
5. Carlos Slim Helú, director of America Movil. Net worth: £49.7 billion ($67.5 billion). Helú used to own a $40 million stake in Shazam and, among a number of assets, controls South American music streaming service Claro Música.
3. Mark Zuckerberg, CEO of Facebook. Net worth: £52.6 billion ($71.4 billion). Zuckerberg founded Facebook in his college dorm room in 2004.
2. Bill Gates, cofounder of Microsoft. Net worth: £66.7 billion ($90.5 billion). Gates now focuses on philanthropy through the Bill & Melinda Gates Foundation.
1. Jeff Bezos, CEO of Amazon. Net worth: £83 billion ($112.6 billion). Bezos has built a retail empire and is the richest man in the world.
