Sometimes the best investments rest on a gut feeling rather than hard numbers. That was certainly true for Jeff Bezos’ parents, who put $245,573 of their retirement savings behind their son in 1995, when nearly everyone else declined.

The backing arrived at a pivotal moment: two years before Amazon would go public, and more than 30 years before the company would surpass Walmart to become the biggest company in the world, clinching the No. 1 on the Fortune 500 as a result—the magazine’s annual ranking of the largest U.S. companies by revenue.

According to Amazon’s 1997 prospectus, the offering document prepared for its initial public offering, Bezos’ mother, Jacklyn Gise Bezos, who died in 2025, and his stepfather, Miguel “Mike” Bezos, gave their son the six-figure sum from their savings so he could get the business off the ground. The money represented a “large fraction” of their life savings at the time, according to Bezos, but it would eventually make them both billionaires.

Before accepting his parents’ money, however, Bezos made it abundantly clear that they might never get it back.

“I want you to know how risky this is,” Mike Bezos recalled his son saying in a 2015 interview. “Because I want to come home at dinner for Thanksgiving and I don’t want you to be mad at me.”

Bezos put the odds that his online bookseller would succeed at about 30%—a figure he previously described as generous, given that the overall success rate for startups is closer to 10%.

A year before his parents invested, Bezos had approached 60 investors, asking for minimum commitments of $50,000 as he sought to reach $1 million in funding. Only 22 of the people he approached agreed to invest, including his parents and two younger siblings, Mark and Christina Bezos Poore. At the $50,000 floor, the 22 commitments added up to at least $1.1 million—enough to clear his target.

His parents made the investment despite the long odds—and, Bezos has joked, despite his stepfather’s first question about the company being “What’s the internet.”

“He wasn’t making a bet on this company or this concept,” Bezos said of his stepfather in an interview with the Academy of Achievement. “He was making a bet on his son, as was my mother.”

“The rest is history”

Almost immediately after Amazon’s online store opened in 1995, Bezos told the Academy of Achievement he was surprised to see orders coming in from all 50 states and from 45 different countries. At the time, the company had about 10 employees. By 1997, it had grown to more than 600—a more-than-sixtyfold expansion in roughly two years.

Amazon went public that year at $18 per share, raising $54 million. Bezos became a billionaire by 1998 thanks to his 40% stake in the company. Today, he ranks as the world’s third-richest person, with a net worth of $283 billion, according to the Bloomberg Billionaire Index.

As for Bezos’ parents, their initial bet turned out to be one of the most successful venture investments of all time. It is unclear how many shares Mike Bezos still holds after his wife died last year, but the couple donated 595,027 shares to the Bezos Family Foundation from 2001 through 2016. If Mike Bezos still retained the rest of their original 1.4 million shares, they would be worth an estimated $51.7 billion at today’s stock price, according to Fortune’s calculations.

Bezos’ siblings Mark and Christina, who each invested $10,000 in Amazon in 1996, according to the prospectus, would also each hold shares worth more than $1 billion today had they never sold any.

Amazon’s shares have skyrocketed more than 208,000% since the company’s IPO in 1997. Just last month, the stock hit its all-time high of $287 per share.

The Bezos family later directed some of the wealth they drew from Amazon toward philanthropy. In 2000, Mike and Jackie founded the Bezos Family Foundation with their three children—Jeff, Mark, and Christina—and their spouses. The foundation has since focused largely on education and child development, funding research and programs aimed at helping young people from birth through high schooln
“We were fortunate enough that we have lived overseas and we have saved a few pennies so we were able to be an angel investor,” Mike said of his and his wife’s initial Amazon investment. “The rest is history.”

This story was originally featured on Fortune.com.