Apple (AAPL) CEO Tim Cook has become a billionaire as he nears a decade at the helm of the world’s most valuable company.

Cook’s estimated net worth — as calculated by the Bloomberg Billionaires index — leaped as Apple shares jumped last week, inching closer to the $2 trillion mark.

Apple’s market cap is currently around $1.9 trillion. Its shares are up nearly 54% so far this year to almost $451 each, outperforming the broader market and the S&P 500 tech sector, according to data provider Refinitiv.

The tech world has produced many billionaires, including the world’s richest man, Amazon (AMZN) founder Jeff Bezos, and Facebook (FB) co-founder Mark Zuckerberg, who Bloomberg pegs as worth $100 billion or more.

But Cook’s new status is something of a rarity because he is not Apple’s founder. Google (GOOGL) CEO Sundar Pichai, for instance, not among Silicon Valley’s richest players. But Google’s co-founders, Larry Page and Sergey Brin, who gave up their executive roles in 2019, are worth about $71.7 billion and $69.5 billion, respectively.

Despite being the top executive at Apple, Cook currently only directly owns “about 0.02% of Apple shares, worth around $375 million,” according to Bloomberg Billionaires, which based its projection of the CEO’s net worth on an analysis of the company’s regulatory filings.

Source: CNN