Index Construction for MDX.GN Series

Vista MDX Indices™ are intended to be accurate and reliable representations of loan performance in the U.S. residential mortgage credit market.The indices themselves are organized into numbered six-month intervals called MDX Series that reference a specific borrower data source. The initial MDX Series will be calculated from data provided to the public by Ginnie Mae and carry the identifier MDX.GN. A new MDX Series is released on the 8th business day of March and September each calendar year.

Below are the rules that are used to determine how loans are selected for inclusion in each MDX Series. Vista will publish these rules on its public website and will provide draft index values for comment prior to final release. See the calendar page for loan selection, draft publication, and final release dates. Loan data is sourced, aggregated, and computed by ICE Data, a division of Intercontinental Exchange, Inc. (NYSE: ICE), based on specifications provided by Vista Index Services.

MDX.GN Loan Inclusion Rules for each new MDX Ginnie Mae Series are followed in the sequential order listed below:

  1. Loan selection takes place the second Friday of February and August each year.

  2. Eligible loans are chosen from the Ginnie Mae MBS pool database during the latest reporting period.

  3. Loans must be contained within a Ginnie Mae II MBS eligible pool.

  4. Loans must have a pool origination date within the most recent eligible six-month window (June – November for March or December – May for September).

  5. Loans must have a loan origination date within twelve months of the Pool Origination Cutoff Date.

  6. Loans must be specified as either Purchase or Refinance type single family mortgages and have an original maturity of 241-360 months at origination.

  7. Loans that previously have been delinquent 30 days or greater, modified, or prepaid are removed.

  8. Immediately prior to Final Production Release, loans are reviewed for any performance changes in the March and September reporting, and loans that are delinquent 30 days or greater, modified, or prepaid are removed.