mazon founder and CEO Jeff Bezos has overtaken Microsoft founder Bill Gates once again to become the world's richest person.

CNBC reported Thursday that Bezos's net worth soared to more than $90 billion after Amazon shares rose sharply overnight. Gates too saw an overnight gain, but a $550 million surge in his net worth brought it to just $88.5 billion, not enough to hold off Bezos.

The Amazon founder previously passed Gates to become the world's richest man in July, but his reign lasted just a day before Gates replaced him. For a day, shares of Amazon stock rose about 10 percent, to $1,067 per share, while Microsoft stock rose by 9 percent, to just under $86 per share.

Gates's position on the Bloomberg billionaires index is lower in part because of his philanthropic giving. Gates, who runs the Bill and Melinda Gates Foundation with his wife, has given away billions throughout his life to charitable causes.

The news follows reports that Amazon is seriously considering a move into the pharmaceutical industry. Earlier this week it was reported that Amazon is beginning to hire personnel in preparation for the move, which is seen by experts as a $25 billion to $50 billion opportunity for Amazon.

The tech giant has reportedly received approval for pharmacy licenses in at least 12 states: Nevada, Arizona, North Dakota, Louisiana, Alabama, New Jersey, Michigan, Connecticut, Idaho, New Hampshire, Oregon and Tennessee.

The online retail giant is also in the middle of a continent-wide search for a city to host a second headquarters. Cities around the United States have been scrambling to win the $5 billion in construction and 50,000 high-skilled jobs that would come with such a venture.