Doesn't always. I have seen penny stocks that have no bid and an ask of .0001 for a very long time until they either delist or reverse split. Funny you bring this up because I am looking for tax losses and found a stock in my account from years ago that had no bid and an ask of .0001. I wanted to write it off as "worthless" so I called Etrade. They told me that generally if a stock still has an ask they don't allow you to write it off as worthless but the girl said she would put the request in for me. Today I got a confirmation that they removed it as worthless. It all depends on the broker. I had another broker who would write off anything as worthless as long as I authorized them to do it, no matter what it was trading at.
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