The fortune of Tesla Inc.’s founder rose $6.1 billion on Friday, according to the Bloomberg Billionaires Index, after the carmaker’s stock surged 11%. Musk is now the world’s seventh-richest person, also ahead of tech titans Larry Ellison and Sergey Brin.

The 49-year-old owns about a fifth of Tesla’s outstanding stock, which comprises the bulk of his $70.5 billion fortune. His majority ownership of closely held Space-X accounts for about $15 billion.

Shares of the electric car-maker have risen 269% this year. The firm’s booming valuation helped Musk land a $595 million pay-day earlier this year, making him the highest-paid CEO in the U.S.

Musk is the latest tech entrepreneur to rise above Buffett in the rank’s of the world’s richest. Steve Ballmer, the former Microsoft Corp. CEO, and Google co-founders Larry Page and Brin also have leapfrogged the Oracle of Omaha. Indian tycoon Mukesh Ambani also surpassed Buffett this week.

Mike Novogratz, the longtime money manager who now runs digital currency investor Galaxy Digital Holdings Ltd., warned that valuations of technology companies are getting way too high and that small investors should get out of the market before it crashes.

“We are in irrational exuberance—this is a bubble,” he said Friday in a Bloomberg Television interview. “The economy is grinding, slowing down, we’re lurching in and out of COVID, yet the tech market makes new highs every day. That’s a classic speculative bubble.”

Buffett’s fortune dropped earlier this week when he donated $2.9 billion in Berkshire Hathaway stock to charity. The 89-year-old has given away more than $37 billion of Berkshire shares since 2006.