As markets there surged, China became a veritable billionaire factory, with more than 50 new billionaires minted in the first half of the year. By July, the bubble had burst. Out of the 50 billionaires created in the first half of the year, only 19 remained billionaires in August.

Russia’s wealthiest continued to experience their own tumult. The country’s richest people lost $55 billion in 2014 after the West imposed sanctions in the wake of President Vladimir Putin’s annexation of eastern Ukraine.


Oil Plunge


This year, plunging oil prices and the enduring chill of sanctions contributed to the country’s first economic contraction in six years. There were 19 Russians on the 400 on Dec. 28 who lost $8 billion during the year. The group was on track to claw back their 2014 losses until June, when the price of oil -- Russia’s biggest export -- began to dive.

Technology was the best-performing industry for billionaires in 2015. The 44 technology billionaires added $81 billion to their total net worth, led by Bezos’s $31 billion rise. Facebook Inc. CEO Mark Zuckerberg became $12 billion wealthier as the social network embarked on a renewed mobile advertising push and its vast audience grew even bigger. Strong ad sales also boosted the fortunes of Sergey Brin and Larry Page, the co-founders of Google parent, Alphabet Inc. They gained a combined $20 billion.


Commodities Rout


The 31 metals, mining and energy billionaires on the index were hit hard as a collapse in prices for oil copper, iron ore and other natural resources shaved $32 billion from their fortunes. Australia’s richest person, Gina Rinehart, lost more than a quarter of her wealth as iron ore plunged by almost half. Rinehart started shipping iron ore from her $10 billion Roy Hill mine this month, boosting global supply which some analysts say could contribute to a further slide in price. She’s the world’s 10th-richest woman with almost $10 billion.

In Nigeria, where tumbling oil prices caused slower growth and the Nigerian Stock Exchange All Share Index dropped 22 percent, Africa’s richest man, Aliko Dangote, suffered his second-straight year of losses. The owner of the continent’s biggest cement producer, Dangote now has $14 billion, about half what he had at his peak in January 2014.

The billionaires cited either declined to comment or didn’t respond to calls and e-mails requesting comment.


Hidden Billions