Jeff Bezos just got a whole lot richer.

Shares of his Amazon.com Inc. surged 12 per cent to US$2,100 in extended trading at 4:16 p.m. in New York, after the largest U.S. e-commerce company reported fourth-quarter results that smashed Wall Street estimates.

Bezos, already the world’s richest person, added US$13.2 billion to his fortune in about 15 minutes. At the current price, his net worth would be about US$129.5 billion, according to the Bloomberg Billionaires Index.

Read more: Amazon holiday results crush Wall Street estimates; shares surge

Bezos, 56, owns about 12 per cent of Amazon’s outstanding stock, making up the bulk of his fortune. His ownership of closely held Blue Origin accounts for about $6.2 billion. The late surge Thursday added more than US$90 billion to Amazon’s market value, pushing it above US$1 trillion.

His ex-wife, MacKenzie Bezos, 49, also has reason to celebrate, as she owns about 4 per cent of the Seattle-based retailer. She started the day as the world’s 24th-richest person, with a US$37.1 billion fortune.

See also: Zuckerberg’s net worth tumbles $4 billion with Facebook dive

Bloomberg’s wealth ranking officially updates after the close of each trading day in the U.S., so Amazon’s latest surge, if it holds, won’t be reflected until after Friday’s close.