Duration

英文名称：Duration 中文名称：久期

衡量债券价格对利率改变的敏感性的首要标准，亦可看为投资者收回其债券投资的资金所需时间的一个指标。久期等于利率变动一个单位所引起的单价变动，如市场利率变动1％，债券的单价变动2，则久期是2。

A measure of the sensitivity of the price (the value of principal) of a fixed-income investment to a change in interest rates. Duration is expssed as a number of years. Rising interest rates mean falling bond prices, while declining interest rates mean rising bond prices.

The duration number is a complicated calculation involving psent value, yield, coupon, final maturity and call features. Fortunately for investors, this indicator is a standard data point provided in the psentation of comphensive bond and bond mutual fund information. The bigger the duration number, the greater the interest-rate risk or reward for bond prices.

It is a common misconception among non-professional investors that bonds and bond funds are risk free. They are not. Investors need to be aware of two main risks that can affect a bond's investment value: credit risk (default) and interest rate risk (rate fluctuations). The duration indicator addresses the latter issue.