AD&Co US Mortgage High Yield Index, Credit-and-Option-Adjusted Spread: Tier 3

The AD&Co US Mortgage High Yield Index crOAS, credit-and-option-adjusted spread, is an extension of the traditional OAS measure. On a set of 20 standardized, probabilistically weighted, market-and-model stress scenarios, AD&Co computes a discount rate that equates expected present value of tranche's cash flows to the observed market price; the cash flows are loss-adjusted using AD&Co's LoanDynamics Model (LDM). Investors and fund managers can use the index to assess the broad market returns, risks and opportunities available through investing in a market-weighted, passive portfolio of US mortgage credit risk transfer instruments. The Index also provides a means of comparing the returns of an actively managed portfolio against a passive, naive market portfolio as approximated by the Index. The Mid-Tier and its sub-indices allow for approximations of performance comparisons by vintage or age, across the capital stack, and by initial credit risk level and/or vintage as indicated by ori