Volatility Indicators
Volatility indicators, such as J Wells Wilder's Average True Range (ATR), attempts to measure the volatility of a security's price action. Day traders prefer increased volatility as the price are more volatile and more money can be gained (or lost) in a short time. Some of the popular volatility indicators include Bollinger Bands, Chaikin's Volatility, Relative Volatility Index (RVI), and Standard Deviation.
In addition to these indicators, the Chicago Board Options Exchange (CBOE) provides a few implied volatility indices, such as the widely used Volatility Index (VIX), the S&P 100 Volatility Index (VXO) and the NASDAQ-100 Volatility Index (VXN).