【中文版】

在股票交易中，平仓是一个常见的操作，指的是将之前买入或卖出的股票进行反向操作，以此取消之前的交易。然而，为什么在平仓时还需要支付一定的费用呢？

首先，我们要明白股票交易本质上是一种合约交易。当投资者买入或卖出股票时，实际上是在签订一份合约。这份合约规定了双方的权利和义务，例如买入方有义务支付款项并接受股票，卖出方有义务交付股票并收取款项。

而平仓实际上是解除这份合约。在解除合约的过程中，需要考虑到双方的权益。如果一方在签订合约后没有违约，那么平仓时应当得到相应的补偿。这种补偿通常由交易所或券商提供，因此需要平仓的投资者支付一定的费用。

另外，交易所在提供平仓服务时也需要投入人力、物力和财力资源，这些成本也需要通过收取平仓费用来得到补偿。

因此，在股票平仓时需要支付一定的费用是为了维护市场公正和稳定，保障投资者的权益，以及补偿交易所和券商的成本投入。

【英文版】

Why do we need to pay money when closing a stock position?

Stock trading is essentially a contract trading. When investors buy or sell stocks, they are actually signing a contract. This contract stipulates the rights and obligations of both parties, such as the buyer's obligation to pay the funds and accept the stocks, and the seller's obligation to deliver the stocks and receive the funds.

Closing the position actually means to terminate this contract. In the process of terminating the contract, the rights and interests of both parties need to be considered. If one party has not breached the contract, they should be compensated accordingly when closing the position. This compensation is usually provided by the exchange or broker, so investors who need to close the position need to pay a certain fee.

In addition, exchanges need to invest in manpower, resources and financial resources when providing closing services, and these costs need to be compensated through closing fees.

Therefore, paying a certain fee when closing a stock position is to maintain market fairness and stability, protect investors' rights and interests, and compensate exchanges and brokerages for their cost investments.