Young Entrepreneur

"You bought it! You are smart! You bought it at Malo Mart!"

Kids can be cute, whiny, mouthy, innocent, bratty, heroic, and even magical. But they can also be good businessmen too.

These children are great with money and are always looking for ways to make more. They always seem to be coming up with one Zany Scheme after another and will always try to cheat other children, and occasionally adults, from their cash. If they're good at it, they could also be a Child Prodigy or a Teen Genius. In shows with a particularly lax depiction of realism, or if the kid's supposed to be just that good, these children could even have their own legitimate companies and firms with actual clients who take them seriously.

Some might become Honest Johns when grown-up.

Examples of Young Entrepreneur include:

Advertising

A Verizon ad features a young girl named Susie who turns a simple lemonade stand into an apparently multi-million-dollar industry, all with the help of a Verizon 4G phone.

Comic Strips

Manolito in Mafalda.
Jenny from the comic Safe Havens.
Lucy from Peanuts is one of the older examples of this trope. She's been selling psychiatric advice to Charlie Brown, whether he wants it or not, for 60 years.

Films -- Live-Action

There's an executive boardroom scene in Hudson Hawk that includes a kid who is presumably one of these.
Dobbs, one of the bullies from Max Keeble's Big Move, has this as his background: he was a millionaire at twelve but lost everything in the stock market, so now he steals lunch money on the pretense he's "investing" it.
The Richie Rich movie has its eponymous character taking over the family corporation while his parents are missing and presumed dead (by everyone but him). He carries on with his dad's tradition of being the antimatter opposite of the Corrupt Corporate Executive.
Chaz from The Royal Tenenbaums.

Literature

From the Ring of Fire short stories, a borderline example and taken as Serious Business with the Sewing Circle; they grow to the age of majority after starting their sewing machine line and investment fund company. Strangely enough, contrary to the trope description, this example is rather realistic. Members of the Barbie Consortium also count as young entrepreneurs.
Artemis Fowl. Teenage billionaire evil genius. Learned everything he knows from his ruthless father, though as time goes by, both Fowl men are less on the evil end of the spectrum.
Artie in Gordan Korman's No Coins, Please comes up with entrepreneur schemes in every state the group hits. Heck, he starts a cow milking business!
Possibly Ur Example: The Great Brain.
John Grisham has such a boy in A Time to Kill.
The Weasley twins in Harry Potter.
Chichikov in Dead Souls. He starts by creating a wax bird and selling it to a classmate, for the money he gets he buys food and sells it to hungry students, and so on.

Live-Action TV

Rico from Hannah Montana.
The entire premise of the Children's BBC series Kerching.
Zach was prone to this in early seasons of Saved by the Bell, though he grew out of it as time went on.
Magnum, P.I.
- Subverted in one episode. Magnum is hired for security for the "vast holdings" of a teenage Cattle Baron. As it turns out it is a con, and the "vast holdings" are rather skinny. But he did do a good job of taking care of his birthright such as it was.
- In the pilot they meet "Snow White", a beautiful Mafia Princess who controls most of the coke in Hawaii. Obviously she is not a nice Young Entrepreneur. She does have style though.
Danny from The Partridge Family. He's the one who got them an agent (among other things).
Cory from That's So Raven and Cory in The House.
Randy from The Wire, who in one instance even continues to pass out campaign material even after getting paid.
Deuce Martinez from Shake It Up, who sells everything from defective watches to counterfeit Lady Gaga tickets.
An episode of Law and Order has a minor witness who owned a nightclub circuit where a shooting took place. A 16-year-old prep school student, he came to the interview armed with a Blackberry and a cutthroat business plan that he explained to the dubious detectives: He doesn't own a permanent property, but instead rents various locations on a night-by-night basis, paying for just enough renovations to bring them up to code as needed. By renting, he eliminates most of the overhead and down profit time of keeping his club open on unprofitable weeknights. Paid admission is handled by bouncers at the door, while drinks are served (for typically insane prices) by an automatic dispenser that eliminates spills and free drinks from bartenders, to say nothing of having to pay the bartenders themselves. All the permits, licenses, and such are handled by an older friend/business partner.

Tabletop Games

Shadowrun
- The sourcebook Runner Havens has a kid in Hong Kong who runs a very popular noodle stand known as "Noodleboy's". According to one of the hackers, the kid's also a money-launderer for one of the Hong Kong Triads.
- During the Crash 2.0, a teenager working part-time at a Stuffer Stack fast food restaurant managed, on accident, to place a stock order for Shiawase at the exact millisecond the Crash caused the stock price to plummet for nanopennies on the dollar. By the time the Crash's aftereffects sorted themselves out, he found himself owning over 4% of one of the largest corporations on the planet. This technically makes him a millionaire on a grand scale, but also puts him way over his head as a major deciding vote between two separate factions of the family-run company, both of whom want him to support their agenda or sell his shares to him. Or else.

Video Games

Malo, the huge fore-headed kid who looks like an infant from The Legend of Zelda Twilight Princess turns out to be a ruthless and savvy businessman when he takes over the shop in the Goron village.
Recette Lemongrass of Recettear: An Item Shop's Tale is forced to become this in order to settle her father's adventuring debts.

Western Animation

Eddy from Ed, Edd 'n' Eddy.
South Park: Cartman was revealed to be this in "My Future Self and Me" Later his future version appears and reveals that, once he changes his lifestyle, he will become a rather successful businessman. He refuses, and future!Cartman immediately becomes a slovenly plumber.
Hiroki Ishiyama from Code Lyoko.
Hustler Kid from Recess.

Real Life

As a general rule, most billionaires became rich in their 20s/30s.
Zuckerberg, anyone? Also Warren Buffett and Michael Dell.
Dragons' Den occasionally features teenagers. The Dragons are noticibly nicer to them then they are to other entrepreneurs, and always compliment them on being so driven at a young age.