CHAPTER 12
Option-Adjusted Spread Analysis
The modified duration and convexity methods we have described are only suitable for use in the analysis of conventional fixed-income instruments with known fixed cash flows and maturity dates. They are not satisfactory for use with bonds that contain
embedded options such as callable bonds or instruments with unknown final redemption dates such as mortgage-backed bonds.
1 For these and other bonds that exhibit uncertainties in their cash flow pattern and redemption date, so-called
option-adjusted measures are used. The most common of these is option-adjusted spread (OAS) and option-adjusted duration (OAD). The techniques were developed to allow for the uncertain cash flow structure of non-vanilla fixed-income ...