6. How can interest rate swap be used to reduce the duration of portfolio to match the
duration of a benchmark?
To reduce the duration so as to match the benchmark, the manager can enter into a swap as the
fixed-rate payer. If the manager wanted to increase the duration, a position in a swap can be
taken to be a fixed-rate receiver. More details are given below.
As with any fixed-income contract, the value of a swap will change as interest rates change.
Dollar duration is a measure of the interest-rate sensitivity of a fixed-income contract. From the
perspective of the party who pays floating and receives fixed, the interest-rate swap position can
be viewed as follows: long a fixed-rate bond + short a floating-rate bond. This means that the
dollar duration of an interest-rate swap from the perspective of a fixed-rate receiver is simply the
difference between the dollar duration of the two bond positions that make up the swap; that is,
We now illustratehow an interest-rate swap can reduce the duration to match the duration of
a benchmark.
Suppose the manager of a portfolio with a market value as of December 31, 2012 of $48,109,810
has a benchmark that is the Barclays Capital Intermediate Aggregate Index. On December 31,
2012, the duration of the index and the portfolio were 2.97 and 3.68, respectively. The manager
wants to restructure the portfolio so that the portfolio’s duration matches that of the benchmark.
That is, the portfolio manager seeks to follow a duration-neutral strategy and therefore the
portfolio’s target duration is 2.97. We know that for a 100 basis point change in rates: