Moving averages are through the oldest and popular instruments used by technicians. Moving average express the average price of a product at a certain moment. Used for an certain title, moving averages do not serve only for determine evolution's trend on long time and variations of exchange course and are sometimes considered as a prevision instrument, more precise, an instrument that can indicate opportune moment for a selling action or buying a title. We are talking about: simple moving average, weighted moving average, and exponential moving average.