(Reuters) – Silicon Valley entrepreneur Elon Musk’s net worth topped $100 billion on Friday, according to the Forbes real-time billionaires list, as the shares of electric-car maker Tesla Inc (TSLA.O) see a more than five-fold surge in value this year.

A large chunk of his wealth comes from the 21% stake in Tesla, according to Forbes. Tesla shares, which went public at $17 a piece in 2010, rose as much as 3.5% in morning trade to a record high of $2,318.49.

The company became the world’s most valuable carmaker by market capitalization on July 1 when it overtook front runner Toyota Motor Corp (7203.T) and has over the last 10 years made many of its retail investors millionaires.

Musk is now part of an elite club of just four others with twelve digit net worth. His nearly $100 billion, however, is just about half the net worth of the world’s richest man and Amazon.com Inc (AMZN.O) CEO Jeff Bezos, according to Forbes.

Musk, who co-founded and sold Internet payments company PayPal Holdings Inc (PYPL.O), now leads some of the most futuristic companies in the world.

Besides Tesla, he heads rocket company SpaceX and Neuralink, a startup that is developing ultra-high bandwidth brain-machine interfaces to connect the human brain to computers.

He set up the Boring Company to make affordable tunnels below busy city streets to for an all-electric public transportation system to avoid the nasty traffic jams in U.S. cities.