An entrepreneur has revealed the secrets behind his success after turning $100,000 into a billion-dollar empire.

Fernando De Leon, 47, of Leon Capital Group made his fortune by investing in businesses other investors might consider 'unglamorous.'

In an interview with the Wall Street Journal (WSJ) he said that when he first started out as a real estate investor in his 20s, he made poor financial decisions and felt he 'wasn’t good' and would quit, but his wife encouraged him to keep going. 

De Leon struck gold by buying distressed properties during the 2008 financial crisis.

Those investments grew into Leon Capital Group, a multibillion-dollar firm that now oversees businesses ranging from insurance to dental practices and med spas.

He says his 'frugal' mindset played a key role in his success.

'I’ve called myself frugal,' he told the outlet. 'When you grow up with few resources, every time you spend money it kind of hurts,' he said of his upbringing along the Mexico-US border.

De Leon added his financial insecurity growing up helped keep him grounded and shaped his understanding of people and American consumers. 

Calling it a 'don’t go broke mentality,' the 47-year-old said it’s an instinctive, constant sense of caution that he embraces. 

'It simplifies the issues that matter - compounding capital, saving, and allocating resources intelligently. That’s the focus,' he told the WSJ. 

He says that mindset gives him an edge in his field, and that he still struggles to justify spending hundreds on dry cleaning or $52 for crab at a restaurant. 

'The expenses add up,' De Leon told the outlet.

'You’re removing the opportunity for winning, or for being right about your investment thesis, every time you accumulate a bad decision.'

Calling himself an 'old-school investor,' he focuses on steady, long-term returns over chasing trends. 

Leon Capital Group oversees 12 independently managed subsidiaries across three divisions: financial services, healthcare, and real estate, according to its website. 

Founded as a modest real estate development company in Texas, Leon has since grown, operating across multiple geographies and industries with thousands of employees. 

In Leon’s real estate portfolio, De Leon has overseen investments valued at over $15 billion.

De Leon began his career as an analyst at Goldman Sachs in New York. He graduated from Harvard College and operates the 'De Leon Family Foundation' which focuses on reducing poverty in South Texas and northern Mexico.