The importance of Stop Loss and Take Profit instructions
An open market order – in other words, a trade at the market price without instructions to close the order is gambling with the total value of your account. You should consider adding stop-loss instructions to all open positions.
i.e. On a long GBP/USD position, you can include a stop-loss instruction that automatically sells your long position if the rate falls to a certain level. The amount that you could lose on any given trade is limited.
Take-profit orders are similar in that they allow you to establish the rate at which you want open positions closed in order to lock-in profits.