Option Adjusted Spread


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Related to Option Adjusted Spread: Effective duration

Option Adjusted Spread

In fixed-income securities with embedded options, the yield spread between two securities calculated as if the embedded options do not exist. Different models calculate the OAS slightly differently, but the basic equation is rendered as:

OAS = yield spread - spread due to the options

This is important in complex derivatives such as mortgage-backed securities. See also: Black-Scholes Model.