The youngest on the list is 19-year-old Alexandra Andresen,...
...followed by her 20-year-old sister Katharina, both from Norway.
The sisters each have a net worth of 1.2 billion dollars...
...which was received from their father's 42% of the family investment company.
Next is 22-year-old Gustav Magnar Witzoe, also from Norway.
His net worth of 1.1 billion was received from his father...
...when Gustav was given 47% equity in his father's company SalMar...
...which is one of the largest producers of farm-raised salmon.
Then, we have 25-year-old SnapChat co-founder Evan Spiegel...
...whose net worth is 2.1 billion.
Rounding out the list is 26-year-old Ludwig Theodor Braun from Germany...
...whose net worth is 1.2 billion.
Ludwig owns just over 9% of his family's medical product company started in 1839.