Forbes tracked the net worth of more than 2,000 billionaires in 2017. The 10 biggest billionaire gainers added a total of $204 billion to their fortunes, compared to a mere $74.7 billion gain in 2016. The publication measured the gains between January 1, 2017 and December 14, 2017.

1. Jeff Bezos

Bezos has a net worth of $98.6 billion and gained $33.8 billion. His company Amazon is having a record year: its stock has rung up a 60% gain since January 1. The stock surged 13% on just one day, October 26, when the e-commerce giant announced third-quarter earnings that far exceeded expectations. That was also the day that Bezos, who gained $7 billion within hours, became the world’s richest person, a title he’s held ever since.

2. Hui Ka Yan

With a net worth of $36.5 billion and gains of $27.4 billion, the world’s richest real estate tycoon Hui Ka Yan’s fortune nearly quadrupled since the start of the year. The jump is entirely tied to a 400% rise in the stock price of his Evergrande Group. Much of that bump came after the company announced strong financial results in July for the first half of the 2017 fiscal year, as revenues increased by 115% and net profits climbed 224%.

3. Bernard Arnault

One of the world's ultimate taste-makers, LVMH's CEO Arnault has long derived most of his fortune from his stake in Christian Dior with a net worth of $63.9 billion, while his current gains estimate up to $23.6 billion. In a deal announced in April, Arnault and his family are buying the shares of Dior they don't already own. Meanwhile, the share price has climbed to 52% since start of the year. Arnault also has a large stake in LVMH, the luxury goods conglomerate he’s run since 1989, which acquired Christian Dior Couture earlier this year.

4. Mark Zuckerberg

Zuckerberg’s net worth is $72 billion, while Facebook has been on a steady roll in 2017, its stock up by nearly 60%, bolstered by growth in mobile advertising. In December 2015, Zuckerberg and his wife, Priscilla Chan, announced they would give away 99% of their Facebook shares for philanthropic causes. Zuckerberg also requested the creation of a new class of shares which would allow him to retain his voting control over the company. After a public outcry, Zuckerberg scrapped the plan in September. The 33-year-old billionaire also announced that he will expedite his philanthropic efforts and sell 35 million to 75 million Facebook shares over the next 18 months to fund a variety of causes.

5. Ma Huateng

Chinese tech billionaire Ma Huateng and Tencent Holdings, where Ma is the chairman, have been hunting for viral communication apps and web hits since 2011. Tencent – which is behind one of China’s most popular messaging apps, WeChat (more than 960 million users) – made a pre-IPO investment in Snapchat and then acquired a 12% stake in its parent company, Snap, in November. Although Snap stock has fallen 35% since its IPO in March, Tencent’s stock is on a tear: it rose more than 100% this year.

6. Mukesh Ambani

The fourth richest person in the world in 2010, Ambani’s current net worth is $41.1 billion and he returns to the ranks of the top 20 for the first time in five years. The surge comes largely thanks to a more than 65% hike in the stock price of his Reliance Industries, which has been on a tear due to rising margins in its petrochemicals business. The company has also delved into India’s hyper-competitive telecommunications landscape with a reasonably-priced business-telecom venture, Jio. Launched in September 2016, its 4G service has attracted 146 million customers to date.

7. Carlos Slim Helu and family

The share price of Mexico’s richest man, Carlos Slim Helu’s telecom corporation, América Móvil, hit a low in November 2016 after a 13-month plunge, but the company has been able to bounce back; in early 2017, Mexican peso rebounded and Slim’s company announced a reassuring first quarter report. Still the biggest wireless telecom and pay TV provider in Latin America, América Móvil share price rose 50% from January through mid-December. Slim also owns 17% of the New York Times, whose stock had its best year since 2013.

8. Yang Huiyan

The richest woman in Asia, Yang Huiyan saw her net worth almost triple this year, thanks to China’s booming real estate market. Yang, who owns 57% of Chinese real estate developer Country Garden Holdings – its stock up by 201% in 2017, owes most of her fortune to her father, Yeung Kwok Keung. Keung founded the Country Garden Group 20 years ago and listed the company on the Hong Kong Stock Exchange in 2007. The company has signed 384 projects globally and sold 3 million homes since 1997.

9. Larry Ellison

Ellison founded his software firm Oracle in 1977 and grew it into a $202 billion (market cap) giant with a surging stock price even 40 years later. From January 1 to December 14, Oracle stock rose 30%. However, after markets closed on Dec. 14, Oracle reported that its cloud services had less revenue than analysts had expected. The stock price plunged nearly 4% on Friday Dec. 15, wiping $2 billion off Ellison's fortune.

10. François Pinault and family

On a November evening in New York, a mystery buyer paid a record price of $450 million for one of Leonardo da Vinci’s few surviving paintings, Salvator Mundi – at François Pinault’s auction house, Christie’s. The auction house is one of the several upscale brands that Pinault and his family owns. Under the umbrella of their international luxury group, Kering, the family oversees an ensemble of luxury goods brands including Gucci, Stella McCartney, Alexander McQueen, and Saint Laurent.