Apple's chief executive Tim Cook is now a billionaire thanks to the company's rising share price.
The 59-year-old's wealth was calculated by the Bloomberg Billionaires Index as Apple's share price has soared during his time in charge, from around $53 (£40) to more than $450 (£343) today.
He joined the technology giant in 1998 at the request of Steve Jobs, who he replaced as chief executive in 2011.
Mr Cook owns more than 847,000 Apple shares directly, worth more than $381m (£291m).
Proceeds from previous share sales, dividends and other compensation add another $650m (£497m) to his net worth, according to calculations by Bloomberg.
Last year Mr Cook was paid $125m (£95m), the majority of which came in the form of vested shares. His basic salary is $3m (£2.3m).
Chief executives of other tech companies, including Facebook's Mark Zuckerberg and Amazon's Jeff Bezos, have a much higher net worth because they often own a large proportion of their company's shares.
Two years ago, Apple became the first US-listed company to be valued at a trillion dollars.
The company is now worth about $1.9tn (£1.45tn) and analysts believe it will pass the $2tn (£1.5tn) mark this year.
Mr Cook has said he will give away his entire fortune before he dies, telling Fortune magazine that he would fund his nephew's education before giving his wealth to charity.
Two causes that are close to his heart are HIV/AIDS prevention and treatment, as well as climate change, he said - telling the magazine he had already started to quietly donate.
"You want to be the pebble in the pond that creates the ripples for change," he said at the time.