When you open a trade, the ask price (Ask) is always used for buying, and the ask price (Bid) for selling. If you want to close a deal, then the opposite price is used: the bid price (Bid) - to close a buy deal and the offer price (Ask) - to close a sell deal. The same principle is used when calculating floating profit or loss. Thus, when opening a new position, one must be prepared for the fact that in order to reach zero, one must always overcome the spread between the purchase price and the sale price.