Definition: A moving average is a common technical indicator used in forex trading. Moving averages have many options, but their basic function is to track the trend. Moving averages are lines that follow the price direction divided by the number you set. If you have an hourly chart open and you want to see the average price over 100 hours, you would set up a 100 period moving average. As each new hour passes, the moving average moves to show the average price movement over the past 100 hours.