In Real Life, owning the majority of a company's stock does not give you absolute power over it. If you own 51% of shares, that still leaves 49% to other stockholders who are still partial owners of the company and retain certain rights — such as appointing people to the board of directors that makes decisions for the company, including appointing a CEO who makes decisions, etc. etc.
In fiction, however, owning controlling interest in a company endows you with godlike power over the organization, making your demands unquestionable and decisions final. So if a character wants to take complete control of a corporation—to change its allegiances, to amass personal wealth, to use it to take over a country or even the whole world, or just for the glory of it—all they need to do is acquire a slight majority of its stock. This majority is almost always stated to be 51% of the voting stock, but the trope still applies if the exact percent is unspecified but still grants the same power as having 100%.
This is a common tactic of Predatory Businesses. Often results in Tyrant Takes the Helm. Easily (and sometimes repeatedly) accomplished by members of the Fiction 500 and characters with Arbitrarily Large Bank Accounts. May be a resolution to Corporate Warfare. For the electoral equivalent, see Decided by One Vote.
Subtrope of Artistic License Economics.
- In Yu-Gi-Oh!, Seto Kaiba is given 2% of the shares to his stepfather's company Kaiba Corp, but has to use them to make 100 times their worth within a year's time. Seto does this by buying 51% of a company and threatening to close it and put everyone out of work unless the original owner buys it back for five times its value, which he agrees to for the sake of the employees. It's implied Seto repeats this with other companies to work up the needed money to please his stepfather. He later takes over Kaiba Corp itself with the same strategy, though this depended on the 2% of shares from Mokuba siding with his older brother at the last second.
- In B.P.R.D.: The Black Flame, Landis Pope calmly walks into the boardroom of Zinco Corperation in a suit of black armour with frog monsters in tow, tells the members that he owns 51% of the company and fires them all with little explanation. He then gets the R&D department to experiment in controlling the frog monsters as part of his plan to gain control of Katha-Hem.
- In The Simpsons comic, "To Heir is Homer", Homer ends up being bequeathed 51% of the shares in Duff Brewery by the will of the previous owner, Sam Duff, with Montgomery Burns controlling the other 49%. He ends up driving the company into the ground with idiotic decisions and is forced to sell the shares to Burns. Fortunately for Homer, it turns out Sam Duff wasn't actually dead (so that 51% had never been actually his to begin with), and Homer had the chance to enjoy something he didn't own for a while.
- In the Eleventh Doctor Year One Doctor Who (Titan) comics, the Doctor buys 51% of the arc-antagonists ServeYouInc through rich friends and a Compound Interest Time Travel Gambit, but is quickly seduced by their evil.
- Ultimate Spider-Man: Once upon a time, the Daily Bugle denounced the Kingpin's acivities. He silenced them by buying stock of the company.
- Hey Arnold! The Movie: Big Bob Pataki initially goes along with Mr. Scheck's plan to bulldoze Arnold's neighborhood and replace it with a mall because he was promised that one of the stores contained therein would be his largest-ever beeper emporium. Later on, however, he reads the fine print of the contract and discovers that in exchange for said beeper emporium, Scheck gets 51% of the shares in his company. Cue one HeelFace Turn.
- Peter LaFleur in DodgeBall: A True Underdog Story buys Globo Gym's controlling stake using the $5 million his team won. He is then able to totally remodel the gym while the original majority shareholder, White Goodman, eats himself back into obesity.
- Averted in Iron Man. While Tony has the controlling share in Stark Industries, Obadiah points out that the board still has rights and was able to file an injunction against Tony when he shut down the company's weapons program.
- In George Cukor's Let's Make Love, Welch buys the 51% of the theater company and when Dumas's going to be fired, he says to the director:
Welch: Your 49 percent wants him out of the show but my 51 wants him in, so he stays in.
- In Mr. Deeds, Chuck singlehandedly votes to sell off Blake Media, putting thousands of employees out of work.
- In the Richie Rich movie, Richie gains control of his parents' company after their apparent deaths due to owning 51% of the company's stock.
- In Scrooge, Scrooge and Marley obtain their wealth by offering to cover the expenses of their owner's embezzlement scandal in return for the right to buy up to 51% of the company's shares. Naturally this gives them absolute power over the day-to-day business of the company.
- At the end of Batman Begins, Bruce Wayne has regained control of Wayne Enterprises by buying controlling interest in it, which he uses to fire CEO William Earle and rehire Lucius Fox into that position.
William Earle: What makes you think you can decide who's running Wayne Enterprises?
Bruce Wayne: Well, the fact that I'm the owner.
Earle: What are you talking about? The company went public a week ago.
Wayne: And I bought most of the shares—through various charitable foundations and trusts and so forth.
- Mission: Impossible II has this as the plan of the Big Bad: to extort Corrupt Corporate Executive John C. McCloy into giving him enough money to buy 51% of his pharmaceutical company, whose stock prices will be sent through the roof when the synthetic "Chimera" virus starts killing people on the streets and the company starts production of the only available vaccine.
- Upon his father's death in Vanilla Sky, David is given 51% control of his father's company, with the remaining 49% split equally between seven board members. A sub-plot in the film revolves around the board's efforts to assume control of David's share and put a stop to the essentially dictatorial control he enjoys over the company despite being an absent-minded Millionaire Playboy.
- In Terry Pratchett's Making Money, Topsy Lavish owned 50% of the Royal Bank of Ankh-Morpork and managed to become Chairman because her dog, Mr. Fusspot, owned the crucial 1%. When she died she left all her shares to her dog and appointed Moist von Lipwig the dog's guardian, effectively making him chairman. The other members of the board want the dog dead, but fortunately Topsy has already arranged a contract on Moist and the assassin's guild won't take another (or the indignity of accepting a contract on a dog); and as long as the dog doesn't die an unnatural death they won't even follow through on it.
- A benign version of this takes place over the course of Anne McCaffrey's The Ship Who Searched. About a third of the way in, Hypatia Cade, a quadraplegic who has been turned into a brainship, is seen telling her stockbroker to invest some of her earnings into a cybernetics company that is apparently not very profitable. Way later, now owning a majority stake, she introduces herself as their new owner. She didn't want to do anything untoward, she just wanted them to build her a robot body so she could have a physical relationship with her human partner Alex.
- Debt of Honor opens with a Japanese investor buying some real estate in Guam, which, combined with various other purchases over the years, resulted in Japan or citizens of it owning 50.016% of the land on that island. This is later used as justification for an armed occupation.
- In Le comte de Monte Cristo, a French miniseries adaptation of The Count of Monte Cristo, the count buys fifty one percent of a bank's shares so he can issue himself infinite letters of credit. Granted, he is good for it.
- Leverage: In "The Snow Job", the team tricks the mark's Idle Rich son to sign over 51% of their company and then proceed to give back the homes that they had tricked people out of. The mark insists they will be able to get the company back, but the team tipped the police off to his violation of the RICO act earlier in the episode and he is arrested before he can do anything to stop the team dismantling the business.
- This comes up in an episode of Dragon's Den where an potential entrepreneur has to choose between an investor who offers her 49% percent ownership of her product and another who offers 50%. She ends up choosing the latter.
- In The Newsroom, Leona's niece and nephew make a bid for 51% of the company's stock, which is narrowly averted. Downplayed in that no one acts like the twins will have ultimate control in the organization—they're just Jerkasses who nobody wants in charge.
- Iron Fist: Upon returning to New York, Danny Rand reclaims 51% of his company and uses his new position to overrule any questionable decision made by the board.
- Shadowrun supplement Corporate Shadowfiles. This is specifically stated to be the case in the future Earth of the game. By standard corporate rules anyone who has more than 50% of the total voting shares can elect anyone they want to the board of directors. The board can then remove and replace corporate leaders, thus granting control of the company.
- The Great Dragon Lofwyr used his hoard to buy 63% of Saeder-Krupp through a series of shell companies and voted himself CEO in 2037, and spent the next decade restructuring the Mega-Corp so that he would be the sole owner while fending off legal and covert ops attempts by the previous CEO to regain control.
- In Noble House (based on the James Clavell novel), mechanically this has a certain truth to it. Each player starts out owning 50% of the "core stock" in their company, with the other 50% held by anonymous investors. As long as the player holds that 50%, they remain unchallenged Tai-pan of their company, but they can be potentially ousted if their ownership falls.
- In The Solid Gold Cadillac, just when the Corrupt Corporate Executives are about to fire Mrs. Partridge from General Products, it's revealed that so many of the small shareholders she befriended by correspondence gifted her shares by proxy that she controls the majority of the voting stock, which allows her to fire the Corrupt Corporate Executives and gain control of the company for herself and McKeever.
- In Civilization V, If you have more than half the delegates to the World Congress, you can effectively force any proposal you want. As host, you get to make a proposal every iteration, and the host gets additional votes. You can use this controlling power to make your religion the world religion and ideology the world ideology, for even more votes.
- In Gex, Gex's mother buys 51 percent ownership in NASA using the money inherited from Gex's great-uncle, fires everyone, sells the rockets to third world countries, and turns Mission Control into "Space Monkeys", a Suck E. Cheese's featuring robotic dancing chimps wearing spacesuits.
- Monty Python's The Meaning of Life the videogame: You have to find stock shares of the Very Big Corporation Of America totalling 51%; then you can take the building (a clip from "Crimson Permanant Assurance" plays).
- The "Fruity Business" mission in Tropico 4 has you working to oust the CEO of Fruitas LTD, a company based on United Fruit Company, the one who gave us the term Banana Republic. To achieve this, El Presidente has to own 51% of the shares and he does this by flooding the market with fruit to lower the price of the shares enough to buy. To get the last 1%, Presidente even has to hire some discount Chinese ninjas to retrieve them from a heavily-guarded fortress in Tibet.
- In Offworld Trading Company your end goal is to make enough money to buy out your competitors, in blocks of 10%. You can also buy up to 50% of your own company's shares to make it more difficult for competitors to buy you out, after buying the outstanding 50% you need to buy the other half all at once in a hostile takeover.
Leela: Zoidberg owned 51% of the company?
- In the episode "Future Stock", after That Guy becomes Planet Express CEO, he buys Zoidberg's shares for a sandwich. When the company votes on selling out to Mom, this turns out to be enough to decide the vote himself.
Hermes: The shares were worthless, and he kept asking for toilet paper!
- The plot of videogame starts when the Professor sells Planet Express to Mom, as it had been losing money for years due to mismanagement. The buyout gives Mom ownership of more than fifty percent of Earth, allowing her to become the supreme ruler of Earth. She then enslaves humanity and starts converting Earth into a giant warship.
- The Pinky and the Brain episode "Snowball" has Bill Grates (actually Snowball the hamster in disguise) being the majority shareholder of the world, thus taking it over before Brain can, owning a 51% share.
- The Simpsons: The episode "The Ziff Who Came To Dinner" plays with this. Artie Ziff, having absolutely nothing else to his name (because his company collapsed as a result of problems including the dot-com bubble bursting, reducing him to House Squatting in secret in the Simpsons' attic for months), bets the company stock he owns in a poker game, which Homer wins. Then at that moment the IRS barge into the Simpson house looking for the CEO of Ziff Co... which at the time technically is Homer. He ends up being taken away with Artie (the man who actually founded the company, led it, and then ran it into the ground) remaining untouched.
- In the Bitcoin community, there was a brouhaha when mining group Ghash.io managed to acquire 51% of the total mining power (after they had promised not to), which could allow them to abuse the system in various ways such as piling on extra transaction fees. They were subject to repeated lynch-mob style DDOS attacks simply due to fears of the hypothetical possibility of abuse.