翻译来自 InvestorWords.com 的 Term of the day（2012/11/28）

Volatility

The relative rate at which the price of a security moves up and down.
Volatility is found by calculating the annualized standard deviation of daily change in price.
If the price of a stock moves up and down rapidly over short time periods,it has high volatility.
If the price almost never changes, it has low volatility.

波动率

证券价格上涨和下跌的相对比率。
波动率通过计算价格每日变化的年度标准差发现。
如果一只股票的价格在很短的时间周期内快速上涨和下跌，那么这只股票具有较高的波动率。
如果（一只股票的）价格几乎从不改变，那么这只股票具有较低的波动率。