中文：

挂单是股票交易中的一种操作，指的是投资者在交易平台或证券公司上提交买卖股票的指令，但并不立即执行，而是等待市场价格达到预期水平时才执行。挂单也被称为“市价委托”，它是一种常见的交易方式，可以帮助投资者在市场波动较大时更好地控制风险和收益。

挂单的优点在于，它可以让投资者在市场价格波动较大时以更合理的价格买卖股票。当市场价格波动较大时，使用挂单可以避免因为手动下单而错失机会或者被市场价格波动所影响。同时，挂单也可以帮助投资者在市场行情不明朗时更好地控制风险，通过预设的止损和止盈点来减少亏损和保护利润。

挂单的种类有多种，包括限价挂单、市价挂单、止损挂单和止盈挂单等。限价挂单可以让投资者以低于或高于当前市场价格买入或卖出股票；市价挂单则以市场价格买入或卖出股票；止损挂单在股票价格下跌到预设的止损价时卖出股票；止盈挂单则是在股票价格上涨到预设的止盈价时卖出股票。

总的来说，挂单是一种方便快捷的交易方式，它可以帮助投资者更好地控制风险和收益，但同时也需要注意风险和技巧。在选择挂单时，投资者应该根据市场情况和个人投资策略做出合理的决策。

英文：

Hanging order is an operation in stock trading, which refers to investors submitting instructions to buy or sell stocks on a trading platform or securities company without immediate execution, but waiting for the market price to reach the expected level before execution. Hanging order is also known as "market order", which is a common trading method that can help investors better control risks and profits when the market is volatile.

The advantage of hanging order is that it allows investors to buy or sell stocks at more reasonable prices when the market price is volatile. When the market price is volatile, using hanging order can avoid missing opportunities due to manual orders or being affected by market price fluctuations. At the same time, hanging orders can also help investors better control risks in uncertain market conditions by预设 stop-loss and stop-profit points to reduce losses and protect profits.

There are various types of hanging orders, including limit orders, market orders, stop-loss orders and stop-profit orders. Limit orders allow investors to buy or sell stocks at prices lower or higher than the current market price; market orders are executed at market prices; stop-loss orders are triggered when the stock price falls to the preset stop-loss price; and stop-profit orders are triggered when the stock price rises to the preset stop-profit price.

Overall, hanging order is a convenient and efficient trading method that can help investors better control risks and profits, but it also requires attention to risks and skills. When choosing hanging orders, investors should make reasonable decisions based on market conditions and personal investment strategies.