Mark Cuban Says the Stock Market Makes Guys Like Elon Musk ‘Insanely Rich’ — But Eliminating Billionaires Would Trigger the ‘Worst Depression’ Ever Seen

Elon Musk crossed a milestone few thought possible earlier this month when SpaceX (SPCX) completed its long-awaited initial public offering (IPO), helping push his net worth past the $1 trillion mark.

The achievement sparked familiar criticism about billionaire wealth. Mark Cuban responded with a different argument: Musk’s fortune exists because millions of Americans decided they wanted a piece of the stock market.

“The reason anyone gets insanely rich is almost always because of the stock market,” Cuban wrote in a post on X on June 13.

That statement wasn’t aimed solely at Musk. Cuban’s broader point was that billionaire fortunes and ordinary Americans’ retirement accounts are more connected than many people realize.

It Starts With 150 Million Investors

Cuban pointed to the roughly 150 million Americans who own stocks either directly or through retirement plans, mutual funds and exchange-traded funds (ETFs).

“And the reason they get rich from the stock market,” he wrote, “is because 150m Americans decided they wanted to own shares of stocks directly, or through their retirement plans, or through other approaches as a way of building their net worth and trying to create a better life for themselves.”

Recent Gallup data tells a similar story. Between 58% and 62% of U.S. adults own stocks in some form, whether through brokerage accounts, workplace retirement plans or investment funds.

For many households, stock ownership isn’t a daily activity. It happens quietly through 401(k)s, IRAs and pension plans. Yet those investments have become one of the primary ways Americans build wealth over time.

Cuban believes that’s an important distinction in conversations about billionaire wealth.

“One Hundred Fifty Million Americans. About 60% of adults," he wrote. “Effectively believing that [Elon Musk] and many billionaires could make them wealthier and help them achieve a better life."

The Market Powers More Than Billionaires

Stock ownership remains uneven across income groups. The top 10% of Americans own roughly 87% to 90% of stock market wealth, while the bottom half owns about 1%.

Even so, market participation has become widespread.

Federal Reserve data shows stocks now account for roughly one-third of U.S. household financial assets. While only about 21% of families own individual stocks directly, ownership rises significantly when retirement accounts and investment funds are included.

That broad participation helps explain why market swings affect far more than professional investors on Wall Street. A rising market can boost retirement balances, pension funds and college savings accounts. A prolonged decline can have the opposite effect.

That’s the backdrop behind Cuban’s warning.

If You Don’t Want Billionaires to Exist…

“If you want [Elon Musk] and most billionaires to no longer be that rich, convince those 150m to sell their stocks, funds, ETFs whatever,” Cuban wrote.

His view is that a mass exodus from stocks wouldn’t simply hurt wealthy founders and executives.

“Of course you would wipe out the net-worth of most of those people, and everyone else’s savings, as the markets crashed and brought down the economy and created the worst depression we have ever seen.”

It’s a dramatic prediction, but it reflects how deeply intertwined household wealth and market performance have become.

Following the 2008 financial crisis, stock ownership among Americans fell to roughly 52%. Participation has since recovered as retirement investing has continued to expand and low-cost index funds have become increasingly popular.

The Next SpaceX Could Be Somewhere Else Today

Cuban’s comments also serve as a reminder of how wealth is created in public markets.

Before SpaceX became a publicly traded company worth more than $1 trillion, it was a risky venture trying to reshape an industry dominated by governments and defense contractors. Investors who believed in that vision early were rewarded as the company grew.

The same search continues today. Investors are pouring capital into artificial intelligence (AI), robotics, biotechnology, advanced energy systems and other emerging industries in hopes of finding the next company capable of transforming a market.

Not every bet succeeds. Most don’t.

But Cuban’s argument centers on a simple reality. Billionaire fortunes are often a byproduct of millions of investors pursuing opportunities they believe can create value over time.

The stock market may produce eye-popping fortunes at the top, but for tens of millions of Americans, it’s also a tool for pursuing retirement security, financial independence, and long-term wealth. That’s why Mark Cuban believes the conversation isn’t just about Elon Musk. It’s about the millions of investors who helped make that fortune possible while trying to build their own.