Secondly, we should consider the expenditure and income of interest. If it is a short-term investment, such as the end of the transaction on the same day, or within one or two days, you don't have to consider interest expenses and income, because the interest expenses and income in one or two days are very small, which has little impact on profit and loss. But for medium and long-term investors, the interest issue is an important link that cannot be ignored. For example, when an investor sells the pound at a price of 1.7000, the price of the pound is still in this position one month later. If the interest on selling pounds is 8%, the monthly interest payment will be as high as $750, which is not a small expense. Judging from the current investment situation of ordinary residents, many investors pay more attention to interest income and ignore the trend of foreign currency, so they all like to buy high-interest foreign currency, and as a result, they lose more because of small losses. For example, when the pound falls, investors buy it. Even if a contract earns interest of $450 a month, the pound drops by 500 points a month, losing $5,000 points. Interest income can't make up for the loss caused by the fall of the pound. Therefore, investors should put the trend of foreign exchange rate in the first place and the income or expenditure of interest in the second place.
Finally, we should consider the expenses of handling fees. Investors buy and sell contract foreign exchange through financial companies, so investors should include this part of the expenditure in the cost. The handling fee charged by financial companies is based on the number of contracts bought and sold by investors, not on profit and loss, so this is a fixed amount.