Do not make the mistake of other newcomers. Use the “Stop loss” - an automatic order to close the transaction at that level of losses that you consider acceptable for yourself.
For example: You open a transaction to sell EUR / USD (euro against dollar). You earn, if the euro falls and respectively bear losses, if the euro rises. “Stop loss” ensures that your loss will not exceed the amount you specify. At the moment when your loss will be equal to that amount, the transaction will be closed automatically, even if you are not near a computer.
For the transaction at “Buy” the price level of “Stop loss” is set below the order price; for the transaction at “Sell” the price level of “Stop loss” is set above the order price. The price levels for the stop-losses are usually determined by the maximum (selling transaction) or minimum (purchase transaction) price of this or the previous trading day.