A stock market trader will often use several "screens" or charts on their computer with different time frames and price intervals in order to try to gain information for making profitable buying and selling (trading) decisions.Often expert traders will emphasize the use of multiple time frames for successful trading. For example, Alexander Elder suggests a Triple Screen approach.Longer-term screen: To identify the long-term trend and opportunitiesMiddle screen: To identify the best dayon which to locate a buy or sell opportunityFiner screen: To identify the optimum intra-day price at which to buy or sell a given security.A market trend is a perceived tendency of financial markets to move in a particular direction over time. These trends are classified as secular for long time frames, primary for medium time frames, and secondary for short time frames. Traders attempt to identify market trends using technical analysis, a framework which characterizes market trends as predictable price tendencies within the market when price reaches support and resistance levels, varying over time.A trend can only be determined in hindsight, since at any time prices in the future are not known.
