Kylie Jenner, the world's youngest "self-made" billionaire, has been collecting designer handbags "for a minute."
"I've been collecting these bags for a minute," the reality television star said in a video showing off her collection on Youtube. "They're also a great investment."
Jenner's collection, which includes at least four Louis Vuitton Graffiti Speedy bags, three Chanel quilted bags, four Gucci Dionysus bags, three Hermes Kelly bags, and 10 Hermes Birkin bags, is stored in a custom-built closet, Jenner's Instagram posts show.
The collection is worth at least £350,000 ($440,335), according to Elle UK. Jenner herself is worth $1 billion.
Phil Knight has a very private collection of books.
The 81-year-old billionaire kept a library attached to his office in the athletic wear giant's office, according to The New York Times. Knight — who has a net worth of $36.2 billion — only let select employees enter, but before they did, Knight required them to take off their shoes and bow. He told The New York Times that he left his book collection in Nike's Beaverton, Oregon offices after he retired in 2016.
"Of course the library still exists," Knight said. "I'm always learning."
Bill Gates collects luxury sports cars.
Bernard Arnault, the richest man in Europe, collects modern and contemporary art.
Michael Dell has a collection of vintage photographs.
Hip-hop mogul Jay-Z collects watches.
"I don't got the bright watch, I got the right watch," Jay-Z raps in his 2006 song "30 Something."
Jay-Z's watch collection includes a Rolex Cosmograph Daytona 116500, an Audemars Piguet Royal Oak, and a custom Richard Mille 56, according to Swiss Watch Expo. Jay-Z is worth $1 billion.
A Rolex Cosmograph Daytona retails for $12,400, according to Rolex's website.