为什么要保证金？

中文：

保证金在金融交易中扮演着至关重要的角色。它的存在主要是为了保护交易双方的权益，确保交易的顺利进行。在许多金融产品和市场中，保证金制度被广泛应用，如股票交易、期货交易、外汇交易等。

首先，保证金可以降低交易风险。交易者只需支付一小部分保证金即可参与大额交易，从而降低了自身的资金压力。同时，保证金制度要求交易者在账户中保持一定的资金，以应对可能的亏损，这有助于防止过度交易和市场操纵行为。

其次，保证金可以提高市场的效率。保证金制度要求交易者必须具备一定的资金实力和风险承受能力，这有助于筛选出更有实力的交易者参与市场，提高市场的整体质量。此外，保证金制度还能促进市场的流动性，使得买卖双方更容易达成交易。

最后，保证金有助于维护市场的稳定。在市场波动较大时，保证金制度可以起到一定的缓冲作用，减少市场的恐慌情绪。同时，保证金制度还可以防止恶意做空和过度投机行为，维护市场的公平性和秩序。

英文：

The margin plays a crucial role in financial transactions. Its existence is primarily to protect the rights and interests of both parties and ensure the smooth conduct of transactions. The margin system is widely used in many financial products and markets, such as stock trading, futures trading, and foreign exchange trading.

Firstly, margin can reduce transaction risks. Traders only need to pay a small portion of the margin to participate in large-scale transactions, thereby reducing their capital pressure. At the same time, the margin system requires traders to maintain a certain amount of funds in their accounts to cover potential losses, which helps prevent excessive trading and market manipulation.

Secondly, margin can enhance market efficiency. The margin system requires traders to possess a certain level of capital strength and risk tolerance, which helps screen out more qualified traders to participate in the market, improving the overall quality of the market. Additionally, the margin system can promote market liquidity, making it easier for buyers and sellers to reach transactions.

Lastly, margin helps maintain market stability. During periods of significant market volatility, the margin system can serve as a buffer, reducing panic sentiment in the market. Simultaneously, the margin system prevents malicious short-selling and excessive speculative behavior, safeguarding market fairness and order.