The 9 richest people in tech

A jump in Amazon's share price has propelled the CEO into top place, knocking Gates off his post after four years running. If this holds until the end of the day's

Technology tycoons continue to dominate lists of the richest people in the world. According to Bloomberg Billionaires Index, one-third of the 30 richest billionaires have earned their fortunes in this sector.

Tech money proves to be hard-earned as well: All nine of the richest billionaires are self-made, thanks to the powerful companies they built themselves, including Amazon, Facebook, Microsoft, and Google.

For the ranking, Business Insider culled data from the Bloomberg Billionaires Index as of July 27, as well as live data from Amazon's share price. The index updates daily to provide up-to-the-minute data on the world's wealthiest men and women. You can read the full methodology here.

Below, read on to see the nine richest billionaires who made their fortunes in tech.

Emmie Martin contributed reporting to an earlier version of this article.

9. Steve Ballmer

Net worth:$30.6 billion

Age: 61

Country: US

Industry: Technology

Source of wealth: Self-made; Microsoft

Steve Ballmer

revenue grew by 294%

After stepping down as CEO, Ballmer fulfilled his dream of owning an NBA franchise, paying $2 billion in a deal to buy the Los Angeles Clippers, now his main venture.

Ballmer's net worth has increased $4.18 billion in the last year.

8. Ma Huateng

Net worth:$31.1 billion

Age: 45

Country: China

Industry: Technology

Source of wealth: Self-made; Tencent Holdings

Software engineer Ma Huateng (aka Pony Ma) founded China's largest internet portal, Tencent Holdings, in 1998. He was 26. Ma's company has a number of successful and widely used platforms in its portfolio, including QQ, its instant-messaging service, which is one of the world's 10 largest websites; a mobile-texting service (WeChat) with over 900 million users; a mobile-commerce product (WeChat Wallet); and an online-gaming community (Tencent Games), the largest in China.

Ma's wealth has increased by $10.3 billion in the past year.

7. Jack Ma

Net worth: $43.8 billion

Age: 52

Country: China

Industry: Technology

Source of wealth: Self-made; Alibaba

$25 billion initial public offering

concerns over counterfeiters trying time for the Chinese economy

6. Sergey Brin

Net worth:$46.8 billion

Age: 43

Country: US

Industry: Technology

Source of wealth: Self-made; Google

Along with cofounder Larry Page, Sergey Brin helped facilitate Google's massive restructuring, which the company announced in 2015. The move put Google under the auspices of a holding company called Alphabet, run by Brin as president and Page as CEO. Google's other ventures, such as Nest and Google X, are separate companies also under the Alphabet umbrella.

The restructuring allowed Brin to focus on exploring inventive new "moonshot" projects and ideas. With top talent and an abundance of resources at its disposal, Alphabet has already started making automated homes and self-driving cars a reality.

Brin, who emigrated from Moscow to the US as a child, connected with Page in 1995 at Stanford, where they were each pursuing a PhD. Three years later they founded Google, now one of the most powerful companies on the planet.

Over the past year, Brin's wealth has increased by $7.62 billion.

5. Larry Page

Net worth:$48.0 billion

Age: 44

Country: US

Industry: Technology

Source of wealth: Self-made; Google

creation of Alphabet self-driving cars

4. Larry Ellison

Net worth:$52.9 billion

Age: 72

Country: US