26.10.2020
Bollinger Bands, a chart indicator developed by John Bollinger, are used to measure a market's volatility. Bollinger Bands consist of a center line and two price channels (bands) above and below it. The center line is an exponential moving average; the price channels are the standard deviations of the stock being studied. The bands will expand and contract as the price action of an issue [http://support.instaforex.com/ar/index.php/%D9%85%D8%B4%D8%A7%D9%83%D9%84_%D9%81%D9%89_%D8%A3%D9%85%D8%B1_%D8%A7%D9%84%D9%81%D8%AA%D8%AD