Here is how the arithmetic works for an investor who rolls over ten-year bonds for the next five years, thus earning 2% more each year than he would by investing in Treasury bills or bank deposits. Assume that the interest rate on ten-year bonds remains unchanged for the next five years and then rises from 2% to 5%.
投资者延长持有十年期证券五年时间，从而每年比投资短期国债或银行存款多赚2%，他最后的结果如何？假设十年期债券利率在未来五年中保持不变，然后从2%升至5%。在这五年中，该投资者每年多赚2%，累计收益10%。但当十年期债券利率升至5%时，债券价格将从100降至69。投资者在债券价格上损失31，三倍于他在利息增加上的收益。