Technical analysis has enjoyed widespread acceptance as a valuable forecasting tool for at least 15-20 years. Technical analysis is not, therefore, infallible and certainly cannot guarantee to predict trends correctly on every occasion. However, it is an extremely useful forecasting tool and widely recognised to be so. Technical analysis is the study of price action, primarily through the use of charts, for the purpose of forecasting future market trends. Prices move in trends.
History repeats itself.
Unless the full significance of this first premise is fully understood and accepted, nothing else that follows makes much sense. It follows, therefore, that a study of price action is all that is required. While this claim may seem presumptuous, it is hard to disagree with if one takes the time to consider its true meaning. All the technician is really claiming is that price action should reflect shifts in supply and demand. If demand exceeds supply, prices should rise.