Modified duration: Difference between revisions
imported>Doug Williamson m (Spacing 22/8/13) |
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== See also == | == See also == | ||
* [[CertFMM]] | |||
* [[Convexity]] | * [[Convexity]] | ||
* [[Duration]] | * [[Duration]] |
Revision as of 14:46, 1 November 2014
(MD).
Modified duration is an estimate of the market price sensitivity of an instrument, to small changes in yield.
It is the 'proportional price change' of a market instrument or portfolio.
The estimate of change in market price is given by:
Modified duration x Starting Market price x Change in yield
Often - but not always - the relevant yield is defined as the annual effective yield ('EAR').
For changes in EAR, modified duration is calculated from Macaulay’s duration as:
MD = Duration/[1+EAR]
For changes in simple annual yields 'R', modified duration is calculated as:
MD = Duration/[1+(R/n)]
where n = number of compounding periods per year.
For example, say Duration = 5.00 years, Semiannual yield R = 6.00% (so n = 2) and so EAR = 6.09%.
With respect to the EAR:
MD = 5.00/1.0609 = 4.71
With respect to the Semiannual yield:
MD = 5.00/1.03 = 4.85
This shows that there would be a greater proportionate change in price for a 1% change in the Semiannual yield, than for a 1% change in the EAR.