Understanding Bollinger Bands
bollinger bands were created by john bollinger in the 1980s as a method for traders to identify extreme short-term prices in a security. the indicator is created by plotting the average of a predetermined number of prices along with two trading bands above and below. the outer bands are created by simply adding and subtracting one standard deviation from the moving average. standard deviation is used to create this indicator because it is a common measure of volatility. under normal conditions, traders will nearly always find a price of a security to trade within the bands. the bands will expand and contract as the price action of a security being studied becomes volatile, expansion, or becomes ? in a tie trading range, contraction. one of the main concept to understand when using bollinger bands is that periods of low volatility generally tend to be followed by periods of high volatility, and vice versa. in other words, if a trader notices that the bollinger bands start to pinch together, then there is a reasonable chance that volatility will increase and a trading opportunity will soon appear. another method of using bollinger bands is to ? when the price of security moves beyond the up or low barriers. when the price moves above the upper band, prices are thought to be overbought, and could be ? for a pullback. conversely, a move below the low band suggests that the price is oversold, triggering a buy signal. bollinger bands have become a top trading tool for a good reason. identifying prices that move beyond the bands helps traders take advantage of unjustifiably high or low prices. it is important for traders to monitor shifts in volatility and few methods accomplish this better than bollinger bands.
- bollinger band・・・ボリンジャーバンド→https://en.wikipedia.org/wiki/Bollinger_Bands