股票为负值是指股票的市值或价格下跌到低于其发行价格或账面价值的状态。这种情况通常发生在市场对该公司的前景或财务状况存在担忧，或者由于公司业绩不佳导致股价下跌。

中文阅读：

当股票价格下跌到低于其发行价格或账面价值时，股票就变成了负值。这意味着投资者已经无法通过卖出股票来收回其投资成本。此外，如果公司的市值或净资产也出现负值，则意味着该公司的财务状况非常糟糕，可能面临破产或重组的风险。

股票为负值的原因可能有很多，例如市场对该公司的前景或财务状况存在担忧、公司业绩不佳、股价被高估等。在这种情况下，投资者需要密切关注公司的经营状况和财务状况，以便及时采取措施来减少损失。

英文阅读：

When a stock's price falls below its issue price or book value, it becomes negative. This means that investors can no longer sell the stock to recover their investment costs. Additionally, if the company's market value or net assets are also negative, it indicates that the company's financial situation is very poor and it may face the risk of bankruptcy or restructuring.

There may be many reasons for a stock to become negative, such as market concerns about the company's prospects or financial condition, poor company performance, or overvaluation of the stock price. In this situation, investors need to closely monitor the company's operating and financial conditions in order to take timely measures to reduce losses.