Though the volatility of any particular ETF is obviously not static, relative volatilities
do tend to be reasonably consistent. The above chart is designed to illustrate changes
in overall market volatility and the relationship between different market segments.
Note: Volatility is the annualized standard deviation of daily returns. i.e. 20-day
Volatility is the standard deviation of the past 20 1-day returns multiplied by
sqrt(252) (annualized). For more information on volatility see
Daily Return Histogram.