Prior to the early 1980s, the bond market was comprised mainly of 'plain vanilla' bonds with simple cashflow structures, where coupon payments and maturity were fixed at the outset.

在80年代以前，债券一般上都相当简单，即包括不太复杂的现金流动结构，票面利率和到期日在发行时已定下。

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The fact that early bonds had no fixed maturity date ensured that any change in interest rate was fully reflected in the capital value of the bond.

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For one thing, it is hard to know how much companies have in fact lengthened the maturity of their debts because the interest-rate swap market allows them to swap those fixed bond payments into cheaper floating debt, a popular strategy in the investment-grade market.

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