Two sisters from Norway, Alexandra and Katharina Andresen, may be just 19 and 20 respectively, but they already have a combined net worth of US$1.2 billion (S$1.68 billion).
On Tuesday (Mar 1), the siblings were named the youngest billionaires in the world in business magazine Forbes' annual ranking of the world's richest people.
They were ranked 1,476th out of 1,810 billionaires on the list.
The sisters' wealth comes from the 42.2 per cent stakes they each hold in private investment company Ferd, which is controlled by their father, Mr Johan H Andresen. He transferred more than 80 per cent of his shares to the girls in 2007, The Telegraph reported.
The company has diverse interests spanning private equity holdings, real estate, security investments and a hedge fund.
According to Forbes, Alexandra, who has just completed high school, is one of the most promising horseback riders in Norway and has won equestrian competitions across Europe.
She has regularly posted various photos and videos showing off her skills and love for horses on her Instagram page.
Meanwhile, older sister Katharina is currently in university, studying social science at Amsterdam University College. She has sometimes complained about the relatively small size of her dorm room on her Instagram page.
According to British tabloid Daily Mail, the sisters previously studied at a prestigious British boarding school. But on their return to Norway, they were enrolled into a local Norwegian state school, and their father insisted that they buy second-hand cars, reported The Telegraph.
Interestingly, the third youngest billionaire on Forbes' latest rankings is also a Norwegian. 22-year-old Gustav Magnar Vitzoe owns a 47 per cent stake in Salmar ASA, one of the world's biggest farmed salmon producers.
While the three youngest billionaires on the list all inherited their families' fortunes, Forbes identified Snapchat CEO Evan Spiegel as the youngest "self-made" billionaire on the list. The 25-year-old, who was also the fourth youngest billionaire ranked, has a net worth of US$2.1 billion.
Microsoft founder Bill Gates was once again named the world's wealthiest person, ahead of Spanish businessman Amancio Ortega and Berkshire Hathaway CEO Warren Buffett.
Facebook CEO Mark Zuckerberg, 31, was the youngest person in the top 10 and also the biggest mover on the list, climbing 10 places to sixth with a net worth of US$44.6 billion.