Amid optimism for Amazon's Black Friday sales, Jeff Bezos' net worth jumped above $100 billion on Friday. The Amazon CEO's fortune reportedly surged $2.4 billion to $100.3 billion, after the retailer's shares grew more than 2 percent on Black Friday. Bloomberg reports: Online purchases for the day are up 18.4 percent over last year, according to data from Adobe Analytics, and investors are betting the company will take an outsized share of online spending over the gifting season. The $100 billion milestone makes Bezos, 53, the first billionaire to build a 12-figure net worth since 1999, when Microsoft co-founder Bill Gates hit the mark. Bezos's fortune rose $32.6 billion this year through Thursday, the largest increase of anyone on the Bloomberg Billionaires Index, a daily ranking of the world's 500 richest people. Amazon have climbed 5 percent this week alone.