Jeff Bezos is the Richest Man in the World. Wealth Just got Wealthier.

The rich aren’t just getting richer — they’re getting much, much richer. 

Citing its Billionaires Index, Bloomberg reported Wednesday that the world’s 500 wealthiest people became almost $1 trillion richer ― that’s $1,000,000,000,000 ― in 2017, thanks largely to booming stock markets. For comparison, that’s over four times as much wealth as they gained last year. 

Amazon founder Jeff Bezos, the world’s richest person, saw the biggest gain in wealth in 2017. He added $34.2 billion to his net worth, which now totals $100 billion.

Mark Zuckerberg, founder of Facebook, and Bernard Arnault, CEO of luxury goods company LVMH, also saw significant increases to their wealth this year. Zuckerberg, ranked by Bloomberg as the fifth richest person on Earth, added about $23 billion to his fortune. Arnault, ranked sixth, saw a $24.5 billion boost. 

As of Tuesday, the 500 billionaires on Bloomberg’s wealthy index had a total net worth of $5.3 trillion ― up from $4.4 trillion in 2016. This year’s total is more than the gross domestic product of Japan or Germany, or that of the U.K. and France combined.

According to Forbes, there are more billionaires walking the Earth than ever before. The magazine said in March that there were a total of 2,043 billionaires in the world ― an increase of more than 230 since 2016.

Of the newly minted billionaires, the greatest number (76) came from China, Forbes said. The U.S. was second, with 25 new 10-figure fortunes.

CNBC’s Robert Frank said this week that while 2017 was a good year for the ultra-rich, 2018 will be a “boom time for billionaires.” The number of millionaires and billionaires will likely “reach an all-time high,” Frank said. And Bezos will likely hold tight to his title of world’s richest. 

Meanwhile, the wealth gap is still growing between the ultra-rich and everyone else, as noted in a Credit Suisse report from earlier this year.

The richest 1 percent now own half the world’s total household wealth, according to the bank’s annual Global Wealth Report. By contrast, the poorest half of adults collectively control less than 1 percent of the world’s wealth.