Kwagmyre Investments, Ltd., hold two bonds: a callable bond issued by Mudd Manufacturing Inc. and a putable bond issued by Precarious Builders. Both bonds have option adjusted spreads (OAS) of 135 basis points (bp). Kevin Grisly, a junior analyst at the firm, makes the following statements (each statement is independent). Apparently, Grisly could benefit from a CFA review course, because the only statement that could be CORRECT is:
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A. B. C. D.D
The "spread over the spot rates for a Treasury security similar to Mudd's bond" refers to the Z-spread on the bond.For a callable bond, the OAS < Z-spread, so this could be a true statement because 135bp < 145 bp.
The other statements are false. The option cost is calculated using the OAS and theZ-spread,not the nominal spread. The cost of the call option should be positive.(The issuer has to compensate for increased uncertainty from the call option.) The static spread (or Z-spread)is the spread over each of the spot rates in a given Treasury term structure,not the spread over the Treasury's YTM.
Following is a more detailed discussion:
The option-adjusted spread(OAS) is used when a bond has embedded options. The OAS can be thought of as the difference between the static or Z-spread and the option cost. For the exam, remember the following relationship between the static spread (Z-spread), the OAS, and the embedded option cost:
Z Spread - OAS = Option Cost in % terms
Remember the following option value relationships: