隔夜利息时间怎么计算

隔夜利息，在外汇交易中是一个重要的概念，它涉及到持仓过夜所产生的利息收支。那么，隔夜利息的时间究竟是如何计算的呢？

首先，我们需要了解外汇交易的结算惯例。根据国际银行惯例，外汇交易通常在 2 个交易日后结算。这意味着隔夜利息是按照结算日来计算的。

具体来看，周一持仓到周二，结算日为周三到周四，所以要支付/收取 1 天利息。周二持仓到周三，结算日为周四到周五，同样支付/收取 1 天利息。需要特别注意的是，周三持仓到周四，结算日为周五到下周一，这种情况下要支付/收取 3 天利息。周四持仓到周五，以及周五持仓到下周一，均支付/收取 1 天利息。

对于不同货币组合的隔夜利息计算方式也有所不同。对于以 USD 为目标货币的组合，例如 GBP/USD，假设是 10K（迷你手 0.1 手）帐户，周一买入 3 手 GBP/USD，市场价是 1.7718/1.7722，持仓过夜至周二，这里英镑是高息货币，美元相对英镑利息较低。比如利息差为 Prmbuy 0.42%（年利息差），则持有英镑的客户会赚取利息，计算方式如下：0.42%/360×10000×3 手×1.7722×1 天 = $0.62 ，也就是年利息平均到天×对应的账户资金×手数×买（卖）价×计息天数。

对于以 USD 为基准货币的组合，比如 USD/JPY，假设是 100K（标准手，1 标准手）帐户，周三卖空 1 手 USD/JPY，市场价是 107.44/107.47，过夜至周四，PrmSell% -2.18，则卖出美元的客户会付出利息，计算方法如下：-2.18%/360×100000×1 手×3 天 = $18.17 。

对于交叉货币的组合，例如 EUR/GBP，假设是 1K（0.01 手）帐户，周五买入 5 手 EUR/GBP，市场价是 0.6885/0.6890，过夜至下周一，PrmBuy% -3.71，则买入欧元的客户会付出利息，计算方法如下：-3.71%/360×1000×5 手×0.6890×1 天 = （￡0.355） = $0.63 。

此外，每逢星期四的时候，加减的隔夜利息会是平日的三倍，因为交割实际发生于周一，隔了周末 2 天。

总之，了解隔夜利息的时间计算方式对于外汇交易者来说至关重要，它可以帮助交易者更好地规划交易策略，控制交易成本。

How to Calculate Overnight Interest Time

Overnight interest is an important concept in foreign exchange trading, which involves the interest income and expense generated by holding positions overnight. So, how exactly is the time of overnight interest calculated?

First of all, we need to understand the settlement practice of foreign exchange trading. According to international banking practice, foreign exchange transactions are usually settled two trading days later. This means that overnight interest is calculated based on the settlement date.

Specifically, holding a position from Monday to Tuesday, the settlement date is from Wednesday to Thursday, so 1 day of interest is paid/received. Holding a position from Tuesday to Wednesday, the settlement date is from Thursday to Friday, and 1 day of interest is also paid/received. It should be noted particularly that when holding a position from Wednesday to Thursday, the settlement date is from Friday to the next Monday. In this case, 3 days of interest are paid/received. Holding a position from Thursday to Friday and from Friday to the next Monday, 1 day of interest is paid/received respectively.

The calculation method of overnight interest for different currency combinations is also different. For combinations with USD as the target currency, such as GBP/USD, assume it is a 10K (mini hand 0.1 hand) account. Buying 3 hands of GBP/USD on Monday, and the market price is 1.7718/1.7722, and holding the position overnight until Tuesday. Here, the pound is a high-interest currency, and the interest of the US dollar is relatively lower than that of the pound. For example, if the interest rate difference is Prmbuy 0.42% (annual interest rate difference), then customers holding the pound will earn interest. The calculation method is as follows: 0.42%/360 × 10000 × 3 hands × 1.7722 × 1 day = $0.62, that is, the annual interest averaged to days × the corresponding account funds × the number of hands × the buy (sell) price × the interest calculation days.

For combinations with USD as the base currency, such as USD/JPY, assume it is a 100K (standard hand, 1 standard hand) account. Selling short 1 hand of USD/JPY on Wednesday, and the market price is 107.44/107.47, and holding the position overnight until Thursday. PrmSell% -2.18, then customers selling the US dollar will pay interest. The calculation method is as follows: -2.18%/360 × 100000 × 1 hand × 3 days = $18.17.

For cross-currency combinations, such as EUR/GBP, assume it is a 1K (0.01 hand) account. Buying 5 hands of EUR/GBP on Friday, and the market price is 0.6885/0.6890, and holding the position overnight until the next Monday. PrmBuy% -3.71, then customers buying the euro will pay interest. The calculation method is as follows: -3.71%/360 × 1000 × 5 hands × 0.6890 × 1 day = (￡0.355) = $0.63.

In addition, on Thursdays, the added or subtracted overnight interest is three times that of ordinary days because the delivery actually occurs on Monday, spanning 2 days of the weekend.

In conclusion, understanding the time calculation method of overnight interest is crucial for foreign exchange traders. It can help traders better plan trading strategies and control trading costs.