Richest family making $5.8m an hour
They are the family behind the biggest department store, but somehow, the Walton clan have largely flown under the radar for decades.
That's despite being the world's wealthiest family, with a $191 billion ($A281 billion) fortune.
And according to Bloomberg, it's a fortune that's growing - fast.
"The numbers are mind-boggling: $70,000 ($A103,000) per minute, $4 million ($A5.8 million) per hour, $100 million per day," the publication reports.
"That's how quickly the fortune of the Waltons, the clan behind Walmart Inc, has been growing since last year's Bloomberg ranking of the world's richest families.
"At that rate, their wealth would've expanded about $23,000 ($A33,868) since you began reading this. A new Walmart associate in the US would've made about 6 cents in that time, on the way to an $11 ($A16) hourly minimum."
It also revealed the family's "jarring" and "near-unprecedented" wealth had soared by $39 billion since June 2018.
But who are the mysterious Walton family, and how did they amass such a "jarring" stack of cash?
Sam Walton was famously frugal, allegedly only flying first class once, living in a modest home and driving a beat-up red pick-up truck.
But Rob, his eldest child, seems to be more happy to splash his cash.
According to Business Insider, he collects valuable vintage cars as a hobby - and in 2013, he managed to total his Daytona Coupe.
It was one of just five in the world and was worth a whopping $15 million.
When John Walton died in a plane crash in the mid-noughties, he left around 17 per cent of his fortune to wife Christy, while the rest was divided between various charities and his son Lukas.
Jim Walton, 71, has an estimated net worth of $US49.6 billion ($A73.2 billion) and is married to Lynne McNabb Walton.
The couple have four children - Alice A Proietti, Thomas L Walton, James M Walton and Steuart Walton, 38, who is a is a Walmart director.
He married Baywatch star Kelly Rohrbach earlier this year.
According to Page Six, "Rumours swirled in March that they were engaged, after author Cat Marnell tweeted that she overheard Walton 'call fiancee Kelly Rohrbach (and) then bitch out … their wedding planner'. She claims to have eavesdropped on Walton saying that their wedding budget was "$1 to $1.5 million".
He and brother Thomas are keen mountain bikers and they co-founded an investment company, RZC Investments.
Alice Walton has a net worth of around $US48.7 billion ($A71.9 billion) and has been divorced twice with no children.
She's a lover of the arts and has amassed a huge personal collection worth $500 million, according to Business Insider.
In 2014, she made history after paying $44.4 million on a Georgia O'Keefe painting - the most ever spent on an artwork by a female artist.
She's also bought and sold a string of luxury, multimillion-dollar properties over the years, including two sprawling Texan ranches and a condo on Park Avenue in New York.
She also donated millions of her Walmart shares to the clan's not-for-profit organisation, the Walton Family Foundation.
According to Bloomberg, the family-owned Walton Enterprises owns half of Walmart, and that 50 per cent stake paid out $3 billion in dividends last year alone.
Somehow, the clan have managed to remain out of the spotlight for the most part, with family members steering clear of social media and avoiding being papped in public despite having a Hollywood star in the ranks.