Josh Luber, the co-founder of Detroit-based StockX, grew up thinking that your personal passions should be separate from your business goals.

But as a diehard sneakerhead, Luber ultimately combined the two in StockX, the largest marketplace in the world for sneakers and streetwear.

While working at IBM as a strategy consultant, Luber had an idea to create a stock market for sneakers and streetwear. His first product, Campless, a price analysis guide for sneakers, got him a meeting with Dan Gilbert, the founder of Quicken Loans and owner of the NBA's Cleveland Cavaliers. When Luber made his pitch, the two discovered they had the exact same idea. In 2016, they took Campless and transformed it into StockX.

Luber has seen StockX achieve massive growth in just five years, increasing from five to 700 employees. His trick to keep from stumbling? Break everything down step-by-step. "Hyper-growth, like anything else, is still just one foot in front of the other. It's just more of them," he says. "Today it's about 'What am I doing right now? How do I get to that next thing?'"

StockX initially focused on selling sneakers, but has expanded into streetwear, watches, and handbags. Luber says that future consumer goods sales will funnel through three companies: eBay, Amazon, and StockX. 

In the early days of StockX, no one had really conceived of the stock market model being used to sell consumer goods, but Luber saw its potential and wasn't afraid to speak up. Still, no matter how strong your idea is, he says, "execution is the only thing that matters."

Correction: A previous version of this article incorrectly stated that Luber is the CEO of StockX.