March 9 (UPI) -- Amazon founder and CEO Jeff Bezos, already regarded as the world's richest person, saw his fortune rise another $30 billion since the start of 2018.
Most of Bezos' wealth, estimated at the start of the year to be about $112 billion, comes from ownership of Amazon stock. Its value has increased about 50 percent in the past six months and added about $10 billion to his net worth in the first two weeks of 2018. The year-to-date change thus far is $30.1 billion, the Bloomberg Billionaires Index indicates.
The index lists Bezos as the world's richest person, with $129 billion, ahead of Microsoft founder Bill Gates at $91.9 billion, investor Warren Buffett at $88.1 billion and Facebook founder Mark Zuckerburg at $74.5 billion.
Over the last year, Fortune reported, Bezos had the largest spike in net worth of anyone on the list in the last 100 years. It added that Bezos became the first centi-billionaire.
Because of the increase in the Amazon stock price, Bezos' net worth is currently growing at the rate of $10 billion per month, or $231,000 per minute, CNN reported on Friday.
It noted, however, that the wealth is based on rising stock prices, or a theoretical paper increase. It does not necessarily mean Bezos could easily convert his investment into cash. Gates has predicted a recession soon and all the billionaires' net worths could decline.