The flag pattern is used to identify the possible continuation of a previous trend from a point at which price has drifted against that same trend. Should the trend resume, the price increase could be rapid, making the timing of a trade advantageous by noticing the flag pattern.
A flag pattern, in technical analysis, is a price chart characterized by a sharp countertrend (the flag) succeeding a short-lived trend (the flag pole). Flag patterns are accompanied by representative volume indicators as well as price action. Flag patterns signify trend reversals or breakouts after a period of consolidation.