With Amazon's share price surging this morning after its earnings report, Bezos's wealth shot up to more than $90 billion, according to calculations by CNBC and data from the Bloomberg Billionaires Index. That put Bezos past Bill Gates to become the richest man in the world.
Gates also added to his fortune this morning with the rise in Microsoft stock after its earnings. But his gain of around $550 million put his fortune at $88.5 billion — not enough to stay ahead of Bezos.
It will be a horse race throughout the day, however. If Microsoft goes up more, or if Amazon slips after the stock starts trading, Bezos could fall back to number two.
This isn't Bezos' first time as numero uno. He became the richest man for the first time in July – but his reign only lasted a day. On July 27, Amazon's share price topped $1,050 and Bezos' paper fortune soared past $90 billion. But after Amazon's share price slipped, Bezos fell back to second place behind Gates.
Here's what makes up the Jeff Bezos empire from CNBC.
At some point, given Amazon's dominance in so many markets, Bezos is likely to pull further ahead in the race for the richest man. For now, however, the battle is between Microsoft and Amazon.
Just after the market's open, Amazon shares were trading up nearly 10 percent at around $1,067, while Microsoft's stock gained 9 percent to trade just under $86.