(I asked a broker friend of mine. This was his explanation, paraphrased)
This happens because of internal in-house shorting. Meaning that the short borrowing may happen internally. When that happens, you may have a situation where if your Client A is long, he might not be able to sell before your Client B who is Short covers.
Scenario:
Client A – Long 5 shares
Client B – Short 5 shares
.. to your clearing firm you are net zero position.
If your client A wants to sell but client B is holding, you would have to short to the street. When there are no locates for the short (as probably happened with GME), you cannot allow your Long client to sell - which means he can lose huge $ and will sue you (and win).
If you as a broker are (as is more likely) "net long" - that is you have, among your clients, more long shares than short, then your longs can sell but only up to the level where your internal book goes flat. After that, if there are no outside locates, you have to restrict longs selling, or buy those shares yourself. In the first case, you invite big litigation which could bankrupt you, and in the second case (this is me guessing here, not my friend talking) you have to be an MM - which Robinhood isn't and, I think, neither is TD Ameritrade - although I think IB is. But in any case, it forces you into a long position on the stock at probably its top, which is a pretty bad move.
You can kinda see why the brokerage would restrict trading in the stock to reduce risk to itself. Outwardly, it definitely looks like a d*ck move. But it's better to survive and be thought a d*ck than to go bankrupt.
This happens because of internal in-house shorting. Meaning that the short borrowing may happen internally. When that happens, you may have a situation where if your Client A is long, he might not be able to sell before your Client B who is Short covers.
Scenario:
Client A – Long 5 shares
Client B – Short 5 shares
.. to your clearing firm you are net zero position.
If your client A wants to sell but client B is holding, you would have to short to the street. When there are no locates for the short (as probably happened with GME), you cannot allow your Long client to sell - which means he can lose huge $ and will sue you (and win).
If you as a broker are (as is more likely) "net long" - that is you have, among your clients, more long shares than short, then your longs can sell but only up to the level where your internal book goes flat. After that, if there are no outside locates, you have to restrict longs selling, or buy those shares yourself. In the first case, you invite big litigation which could bankrupt you, and in the second case (this is me guessing here, not my friend talking) you have to be an MM - which Robinhood isn't and, I think, neither is TD Ameritrade - although I think IB is. But in any case, it forces you into a long position on the stock at probably its top, which is a pretty bad move.
You can kinda see why the brokerage would restrict trading in the stock to reduce risk to itself. Outwardly, it definitely looks like a d*ck move. But it's better to survive and be thought a d*ck than to go bankrupt.
