During the dot-com boom era, Musk was a co-founder of the original X.com, which ultimately became PayPal (PYPL -3.31%). He was CEO of PayPal until 2000 and owned 11.7% of the company's shares at one point. He no longer has a stake in PayPal, although he owned shares before the company was acquired by eBay (EBAY -1.32%) in 2002.
Musk received more than $100 million for his stake after cashing out. Today, his PayPal stake would be worth billions of dollars. However, since he used the proceeds to fund both Tesla and SpaceX in their early days, it's tough to make the case that cashing out was a bad move.
Elon Musk's private equity
Musk founded and still controls several companies, but SpaceX is the largest by far. He owns about 42% of the space exploration technology company, which was valued at roughly $400 billion in July 2025.
In addition to SpaceX, Musk has majority ownership of several other privately owned start-ups he founded or co-founded, most notably:
Elon Musk's cryptocurrency investments
Although we don't know the exact amounts he owns, we do know that Musk is a cryptocurrency investor, both through the companies he controls and personally. He has been quite outspoken about some of his favorite digital assets, particularly Dogecoin (DOGE -7.42%).
Musk has also revealed that he owns Bitcoin (BTC -7.07%) and Ethereum (ETH -12.41%) and has stated that his Bitcoin is worth much more than his Ethereum or Dogecoin.
Tesla and SpaceX both own significant amounts of Bitcoin, too. Although we know Tesla owned 11,509 Bitcoins as of June 2025 (worth more than $1 billion at the time), we don't know how much of any cryptocurrencies Musk personally owns.