Stocks that ultimately fall to zero generally follow a fairly predictable path. Usually, s stock will begin trading down in value as the underlying company experiences financial difficulty and may be on the verge of bankruptcy. If and when bankruptcy is declared, the company's stock will leave the major exchanges and trade between speculators. Ultimately, the stock will be rendered worthless and will become merely a souvenir. Even in this event, the stock can still usually be sold for tax loss purposes.