In a traditional market, volatility is a measure for variation of price over time. Normally, a higher number means that there is a higher risk in the investment. Bitcoins however defy traditional logic and do not ever decline, so while they still have a large volatility, it is because they go up consistantly. It is this property that allows investors to buy high and sell low with no losses.
"Up, down, up, down, on the way to the top!" - Bruce Wagner