Tuning Support

MBS Prepayment Model Tuning Parameter Recommendations
[5.2f - 5.2g version]

Update: 1/ 2010 (previous tuning release, dated 7/ 2009 were replaced and can be found here).
We updated our recommended tunings for v5.2f of the prepayment model to account for recent developments. Versions 5.2g and 5.2f now share the same recommended tuning set.  While normally tunings are tied to a particular model version, since the updates to v5.2g were unrelated to market development, we felt that updating the v5.2f tuning set would not result in any double counting effects and wanted  v5.2f users to benefit from an updated set of tunings.

Please note that some vendor systems have specific instructions for adjusting AD&Co tuning parameters. Please click here for vendor-specific information.

FIXED RATE AGENCY LOAN TYPES (Overall Tunings)

 

Loan Type	Scale	Refi	Slide	Tuning Start Year	Tuning Start Month	Tuning End Year	Tuning End Month	Tuning Ramp Months	Tuning Fade Months
FN30	0.65	0.55	40	2007	6	2010	12	12	24
FG30	0.65	0.55	40	2007	6	2010	12	12	24
FN15	0.75	0.4	0	2007	6	2010	12	12	24
FG15	0.75	0.4	0	2007	6	2010	12	12	24
FN10	1	0.25	0	2007	6	2010	12	12	24
FN20	0.6	0.5	0	2007	6	2010	12	12	24
FG20	0.6	0.5	0	2007	6	2010	12	12	24
FH5YRB	0.4	1	50	2007	6	2010	12	12	24
FH7YRB	0.4	1	50	2007	6	2010	12	12	24
FN7YRB	0.4	1	50	2007	6	2010	12	12	24
GN30	0.85	0.8	30	2007	6	2010	12	12	24
GN15	0.85	0.9	50	2007	6	2010	12	12	24
RELO30	0.75	0.5	40	2007	6	2010	12	12	24
RELO15	0.65	0.5	40	2007	6	2010	12	12	24

Please click here for vintage specific Fixed Rate tunings

 

ADJUSTABLE RATE AGENCY LOAN TYPES (Overall Tunings)

Loan Type	Scale	Refi	Slide	Tuning Start Year	Tuning Start Month	Tuning End Year	Tuning End Month	Tuning Ramp Months	Tuning Fade Months
FN 1/1	0.4	0.5	0	2007	6	2010	12	12	24
FN 3/1	0.5	1	0	2007	6	2010	12	12	24
FN 5/1	0.5	1	0	2007	6	2010	12	12	24
FN 7/1	1	0.55	0	2007	6	2010	12	12	24
FN 10/1	1	0.5	0	2007	6	2010	12	12	24
FG 1/1	0.45	0.5	0	2007	6	2010	12	12	24
FG 3/1	0.45	1	0	2007	6	2010	12	12	24
FG 5/1	0.45	1	0	2007	6	2010	12	12	24
FG 7/1	1	0.55	0	2007	6	2010	12	12	24
FG 10/1	1	0.65	0	2007	6	2010	12	12	24
GN 3/1	1	0.75	0	2007	6	2010	12	12	24
GN 5/1	1	0.85	0	2007	6	2010	12	12	24

Please click here for product specific (standard vs IO) ARM tunings

All Agency loan types with parameters not listed above should be set to 1.0 with the exception of slide which should be set to 0.

FIXED RATE NON-AGENCY LOAN TYPES (Overall Tunings)

 

Loan Type	Turnover	Refi	Slide	Tuning Start Year	Tuning Start Month	Tuning End Year	Tuning End Month	Tuning Ramp Months	Tuning Fade Months
NAPrime 30	1	0.75	200	2007	6	2010	12	12	24
NAPrime 15	1	0.75	75	2007	6	2010	12	12	24
Subprime 30	0.75	0.85	225	2007	6	2010	12	12	24
Subprime 15	0.85	0.85	225	2007	6	2010	12	12	24

 

ADJUSTABLE RATE NON-AGENCY LOAN TYPES (Overall Tunings)

Loan Type	Slide	Refi	Scale	Turnover	Tuning Start Year	Tuning Start Month	Tuning End    Year	Tuning End Month	Tuning Ramp Months	Tuning Fade Months
NA 3/1	200	0.65	0.85	1	2007	6	2010	12	12	24
NA 5/1	200	0.85	1	1	2007	6	2010	12	12	24
NA 7/1	100	1	1	1	2007	6	2010	12	12	24
NA 10/1	100	1	1	1	2007	6	2010	12	12	24
Subprime 2/28, 3/27, 5/25	100	0.85	1	1	2007	6	2010	12	12	24
Option ARM	125	0.5	1	0.85	2007	6	2010	12	12	24

 

Please click here for product specific (standard vs IO) ARM Non-Agency tunings

All Non-Agency loan types with parameters not listed above should be set to 1.0 with the exception of slide which should be set to 0.