Sometimes, you look at a wildly successful company, and it just clicks—of course, it works, and of course, it made millions. But hindsight is always 20/20. The real challenge? Spotting that golden opportunity when it's just an idea on paper and your own money is at stake.

Mark Cuban has built a fortune on his ability to see potential early. He became a billionaire after selling Broadcast.com to Yahoo for $5.7 billion in 1999, later parlaying that wealth into everything from owning the Dallas Mavericks to becoming a fan-favorite investor on "Shark Tank." But even billionaires don't bat a thousand.

For Cuban, one of his biggest financial missteps was passing on an early investment in Uber (NYSE:UBER) —a decision that cost him billions.

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The $250,000 That Could Have Turned Into $4.12 Billion

Back in 2009, Uber co-founder Travis Kalanick approached Cuban with a chance to invest in the then-fledgling ride-sharing startup. The valuation? $10 million.

"Just think: If I would've given him $250,000 on a [$10 million] valuation, it'd be billions," Cuban said during an appearance on Kevin Hart's "Hart to Heart."

And he's not wrong. If Cuban had invested $250,000 for a 2.5% stake in Uber at a $10 million valuation, that stake would have been worth $2.05 billion when Uber went public in May 2019 at an $82 billion valuation.

That means Cuban missed out on a 819,900% return. Now, nearly six years later it's even more of a sting. 

His shares would be worth $4.12 billion today, based on Uber's $165 billion market capitalization as of this month 2025.

The return on investment would be approximately 1,647,900%. 

"I mean, I've done OK. But, still," said Cuban, whose net worth sits at an estimated $5.7 billion.

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A History With Kalanick—And a Price That Didn't Feel Right

So when Kalanick pitched Uber, Cuban was intrigued.

"He comes to me, like, first off [and says]: ‘I've got this thing. It's going to replace taxi cabs…'" Cuban recalled. "I was like, ‘I love it.'"

But then came the valuation.

Cuban balked at the $10 million price tag. "I said, ‘I'll do it at [a] $5 million valuation…' for Uber!" he told CNBC.

That counteroffer didn't go over well. "[Kalanick] never came back to me. He got somebody else. Whoops," Cuban admitted.

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Even Kevin Hart Missed Out

Turns out, Cuban wasn't the only one who failed to see Uber's potential. Hart also had a shot at investing but turned it down for an even simpler reason—it just sounded ridiculous.

Hart recalled that Uber investor and music manager Troy Carter tried to get him in early, but the idea of sharing a ride with strangers seemed absurd. "Sounds like Murderville," he said.

That skepticism cost him—big time. Hart estimated that his would-be investment of up to $75,000 could have netted him "$100-plus million" if he had jumped in.

Learning From the Mistake

Cuban didn't just turn down Uber—he also warned Kalanick about the roadblocks ahead. He correctly predicted that the company would face regulatory nightmares and resistance from taxi commissions trying to shut it down.

But missing out on Uber taught him a lesson: sometimes, gut instinct and early adoption matter more than haggling over valuation. And this time, he wasn't going to let an opportunity pass him by.

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Cuban's $7.35 million investment in Fetii, alongside Y Combinator and Goodwater Capital, proves he's serious about not making the same mistake twice.

At SXSW in 2017, he made it clear: "If you really believe and you really have something that you think is going to disrupt the world, bring it to me," he said. "I won't make the same mistake twice."

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