Say there is a very rich, very unpopular individual. This individual wishes to buy millions of dollars in stock in a company he or she thinks will be successful. The company, however, realizes that by being associated with this person they will become vulnerable to certain political/social actions such as boycotts.

Can this company block said individual from purchasing the company's stock in the market?

  • 3
    I don't know enough about this to write up a proper answer, but some companies have attempted to fend off hostile takeovers by issuing more stock so that the buyers could not acquire a majority of the shares. en.wikipedia.org/wiki/Shareholder_rights_plan
    – zwol
    Jan 31, 2017 at 22:06
  • 5
    Companies don't sell their stock, usually. The stock is already out there on the market, shares owned by investors. The only time when a company actually sells it's stock is offering, which is quite rare event in a company lifetime.
    – Agent_L
    Feb 1, 2017 at 9:07
  • 9
    A company can refuse to sell the stock it owns, just as I can refuse to sell mine. You are asking if it can stop someone from buying the stock from the market, not from the company. Feb 1, 2017 at 12:35
  • @zwoi - the macaroni or poison pill, macaroni because the stock swells like macaroni in the pot.
    – mckenzm
    Feb 2, 2017 at 6:31
  • 1
    @the_lotus nonsense. Feb 2, 2017 at 14:10

5 Answers 5


I assume you are talking about a publicly traded company listed on a major stock exchange and the buyer resides in the US. (Private companies and non-US locations can change the rules really a lot.)

The short answer is no, because the company does not own the stock, various investors do. Each investor has to make an individual decision to sell or not sell. But there are complications. If an entity buys more than about 10% of the company they have to file a declaration with the SEC. The limit can be higher if they file an assertion that they are buying it solely for investment and are not seeking control of the company. If they are seeking control of the company then more paperwork must be filed and if they want to buy the whole company they may be required to make a tender offer where they offer to buy any and all shares at a specific price. If the company being bought is a financial institution, then the buyer may have to declare as a bank holding company and more regulations apply. The company can advise shareholders not to take the tender offer, but they cannot forbid it.

So the short answer is, below 10% and for investment purposes only, it is cash and carry: Whoever has the cash gets to carry the stock away. Above that various regulations and declarations apply, but the company still does not have the power prevent the purchase in most circumstances.

  • 13
    For a short answer, you go into some long-winded detail. +1 anyway. Jan 30, 2017 at 23:12
  • 41
    What can I say? Buying a substantial fraction of a company is complicated.
    – zeta-band
    Jan 31, 2017 at 0:36
  • 2
    You might also mention what happens if they offer to buy the entire company and an individual investor doesn't want to sell. +1 great answer otherwise.
    – user541686
    Jan 31, 2017 at 1:27
  • 7
    @Mehrdad i guess doesn't matter. As long as Mr Devil owns 99% and Mr Stubborn owns 1% mr devil can do anything he wants.
    – vasin1987
    Jan 31, 2017 at 5:00
  • 6
    In the UK, you only have to buy a certain percentage (high 90s) and then you can legally force other shareholders to sell their holdings so you can take the company completely private.
    – user45974
    Jan 31, 2017 at 12:19

A more serious problem: how do you know who's really buying your stock?

"Shell companies" are an increasingly obvious problem in corporate and tax accountability. There are jurisdictions where companies can be created with secret lists of directors and shareholders. If stock is bought by one of these companies, it is very hard to trace it to a particular individual.

  • 12
    On the bright side, if the individual secretly owns the company's stock through shell companies that nobody has penetrated, then the company won't (yet) suffer from the individual's unpopularity :-) Jan 31, 2017 at 12:29
  • 8
    As phrased, this is more of a comment than an answer. It could be rephrased to point out that this makes it logically impossible to stop specific individuals. Jan 31, 2017 at 13:55
  • 1
    Christopher Nolan's Batman did just that. Jan 31, 2017 at 15:00
  • 6
    @GaneshSittampalam: that implication is pretty obvious already.
    – smci
    Feb 1, 2017 at 7:55

In the UK, this is the very definition of a Public Limited Company. A Limited Company can restrict how its stock is trades and who can buy and sell and when, a Public Limited Company cannot.

Most stock exchanges will only allow Public Limited Company stock to be traded.

Therefore a company can control who its stock holders are or be traded on a Stock Exchange.

  • This seems to get to the heart of the matter. In most jurisdictions there are probably legal mechanisms you could use to restrict who stock can be held by, but exercising them is almost surely going to preclude trading on public stock exchanges. Feb 1, 2017 at 22:49
  • The law can also prevent purchases, as can letters of offer to employees.
    – mckenzm
    Feb 2, 2017 at 6:32
  • @mckenzm, that does not prevent someone purchasing or holding stock, it just stops them keeping their job is they do so.....
    – Ian
    Feb 2, 2017 at 9:39

The company could use registered shares with restricted transferability, i.e. shares that require the consent of the issuing company for a change of ownership.


The answer to this question is given by the fact that many public companies have people who are opposed to the company's aims or practices and who own their stock, often a single share, for the purposes of turning up to shareholder meetings and haranguing directors/asking awkward questions/disrupting proceedings, etc.

If public companies could stop these campaigning shareholders from owning stock they would.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .