The issue is one of margin calling, and other institutions being unwilling to lend you infinite amounts of money.
Even if your investment strategy is sound, if in the short term, you on paper owe stock that is "worth" billions of dollars, the institutions that you are owning this paper billions of dollars too, could be unwilling to just trust that you will be able to pay it.
Thus, they bake in contractual provisions, such as margin calls, which require you to automatically sell/buy the stock back, if you ever reach certain loss limits. Thus, forcing you to accept the loss now, even if your long term strategy is hypothetically profitable.
Or, at least that is the simplest/most common ways that this work. I am sure that margin calls are more complicated than that, for large financial institutions.
An unlisted stock is still a stock, you still have to have a borrow for it until the company is fully wound up (which could be years after being delisted).
Even if your investment strategy is sound, if in the short term, you on paper owe stock that is "worth" billions of dollars, the institutions that you are owning this paper billions of dollars too, could be unwilling to just trust that you will be able to pay it.
Thus, they bake in contractual provisions, such as margin calls, which require you to automatically sell/buy the stock back, if you ever reach certain loss limits. Thus, forcing you to accept the loss now, even if your long term strategy is hypothetically profitable.
Or, at least that is the simplest/most common ways that this work. I am sure that margin calls are more complicated than that, for large financial institutions.