Alexandra, a dressage competitor (one of the highest forms of horse training), debuted on the Forbes 2016 list of world's richest people after amassing a fortune of $1.2 billion.
The teenager is heir to her family's fortune in the tobacco industry, which dates back to the 19th century, reports Forbes.
Alexandra currently owns 42.2 percent of private investment company Ferd, a "holding company with diverse interests spanning private equity holdings, real estate, security investments and a hedge fund," according to the publication.
Alexandra's sister, 20-year-old Katharina Andresen, who also owns 42.2 percent of Ferd, made the list as well.
The two stylish sisters rank as the 1,475th wealthiest people on the planet, and are in the top ten richest people under 30.
Alexandra and Katharina's great-great-great grandfather Johan Henrik Andresen took over Tiedmanns tobacco factory in 1849. The family stayed in the industry until 2005 when they sold their share for $500 million to invest in property and hedge funds, says Forbes.
Today, their father, Johan H. Andresen, still has 15.2 percent of Ferd Holdings. While his daughter's own over 80 percent of the investment company.
When details of Alexandra and Katharina's wealth were first published in 2014, Katharina, a freshman studying social science at Amsterdam University College, received 500 new friend requests on Facebook, according to Forbes.
On the Ferd wesbite, Alexandra, who just finished high school, says she feels a "great responsibility" to ensure her company's success.
"I want to help develop Ferd and make it even better," her statement reads.