It's more than 20 years since Mike and Jackie Bezos took a gamble and poured a large part of their retirement fund into their son's idea: an online bookshop.
But that online bookshop morphed into Amazon, the nature of shopping changed forever, and Mr and Mrs Bezos's investment now looks very clever.
The couple contributed $245,573 (£187,120) to son Jeff's venture in 1995, a year after he started the company.
While it is not clear how many shares they still own, it is thought it could be in the realm of 16.6 million – 3.4% of the company.
This would make them the second-biggest owners after their son.
The Bezos parents's holdings have not been public since 1999 but Bloomberg calculates that, depending on how many shares they have kept, they could be worth up to $29.6bn (£22.5bn).
It has been reported that they donated 595,027 shares to the Bezos Family Foundation, which focuses on education for young people, between 2001 and 2016.
The 25,000 they donated in 2016 were worth about $20m (£15.2m) at that time, according to Bloomberg.
Bezos's siblings Mark and Christina also bought shares during Amazon's early days and the 30,000 they got for $10,000 in 1996 could be worth around $640m (£487m) today.
Jeff Bezos, 54, is now the richest man in modern history, with a fortune of $150bn (£114bn), tens of billions of pounds ahead of the next richest – Bill Gates.
On Friday, shares of Amazon rose 4%, hitting an all-time high after the online retailing giant's quarterly profit topped $2bn (£1.5bn) for the first time, with its best operating margin in 13 years.
Amazon's stock price has increased more than 54% since the start of the year and it has a market value of $916.97bn (£698bn).
In a 2013 interview with CNBC, Mike Bezos said: "Jeff approached us with his crazy idea of opening a bookstore on the internet but we believed in Jeff and what he could do."
Wife Jackie added: "It was an investment in Jeff, not in an as-yet-unnamed company.
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"If he had followed my original advice – can't you do this on the weekend or after work? – we probably wouldn't be buying so much online right now.
"The investment we've made in young people (through the foundation) has paid off every bit as our investment in Amazon."