New York, July 09, 2009 -- Moody's Investors Service has downgraded the ratings of 32 tranches from
six RMBS transactions, backed by prime Jumbo loans, issued
by Thornburg Mortgage Securities Trust in 2002, 2003, and
2004.
The collateral backing these transactions consists primarily of first-lien,
adjustable-rate, jumbo residential mortgage loans.
These actions are a result of Moody's updated loss expectations
on the underlying collateral relative to available credit enhancement.
Moody's methodology for rating securities backed by pools of jumbo
mortgages originated prior to 2005 takes into account the annualized loss
rate from the last 12 months ("Recent Losses") and the projected
loss rate over the next 12 months ("Pipeline Losses"),
and then translates these measures into lifetime losses based on a deal's
expected remaining life.
Recent Losses are calculated by assessing cumulative losses incurred over
the past 12-months as a percentage of the average pool factor for
the previous year. Pipeline Losses are calculated by using annualized
roll rates of 15%, 30%, 65% and 90%
for loans that are 60-89 days delinquent, 90 or more days
delinquent, in foreclosure, and properties that are held for
sale (REO) respectively. Moody's then applies loss upon default
(severity) assumptions ranging from 25% to 35% on the loans
that are projected to default,. The roll-rates and
severity assumptions mentioned above can vary from deal-to-deal,
depending on a deal's specific characteristics.
Weights are then applied to Recent Losses and Pipeline Losses.
The weights applied depend on the year of loan and RMBS origination --
deals from earlier vintages typically experience higher Recent Losses
and, as a result, have higher weights on Recent Losses.
The weighted loss is then translated to lifetime projected loss depending
on the deal's expected remaining life by which is estimated based
the deal's pool factor and prepayment speeds.
Moody's final rating actions are based on i) the level of credit
enhancement available relative to the updated pool-level loss expectations
and ii) current ratings. In addition, Moody's takes
into account credit enhancement provided by seniority, cross-collateralization,
time tranching, and other structural features within the priority
of payments.
List of actions:
Thornburg Mortgage Securities Trust 2002-3
Cl. B-1, Downgraded to Aa1; previously on 7/27/2005
Upgraded to Aaa
Cl. B-2, Downgraded to A1; previously on 7/17/2006
Upgraded to Aa1
Cl. B-3, Downgraded to Baa3; previously on 7/27/2005
Upgraded to A2
Thornburg Mortgage Securities Trust 2003-1
Cl. B-1, Downgraded to Aa1; previously on 7/27/2005
Upgraded to Aaa
Cl. B-2, Downgraded to A1; previously on 7/27/2005
Upgraded to Aa2
Cl. B-3, Downgraded to Ba1; previously on 2/18/2003
Assigned Baa2
Cl. B-4, Downgraded to B2; previously on 7/27/2005
Upgraded to Ba1
Cl. B-5, Downgraded to Ca; previously on 2/18/2003
Assigned B2
Thornburg Mortgage Securities Trust 2003-3
Cl. B3, Downgraded to A3; previously on 7/17/2006 Upgraded
to A2
Cl. B4, Downgraded to Baa3; previously on 7/17/2006
Upgraded to Baa2
Cl. B5, Downgraded to B2; previously on 7/17/2006 Upgraded
to Ba2
Thornburg Mortgage Securities Trust 2004-2
Cl. A-1, Downgraded to Aa2; previously on 7/27/2004
Assigned Aaa
Cl. A-4, Downgraded to Aa2; previously on 7/27/2004
Assigned Aaa
Cl. A-X, Downgraded to Aa2; previously on 7/27/2004
Assigned Aaa
Thornburg Mortgage Securities Trust 2004-3
Cl. A, Downgraded to Aa2; previously on 10/11/2004 Assigned
Aaa
Cl. A-X, Downgraded to Aa2; previously on 10/11/2004
Assigned Aaa
Cl. B1, Downgraded to A3; previously on 10/11/2004 Assigned
Aa2
Cl. B2, Downgraded to Ba1; previously on 10/11/2004
Assigned A2
Cl. B3, Downgraded to B3; previously on 10/11/2004 Assigned
Baa2
Cl. B4, Downgraded to Ca; previously on 10/11/2004 Assigned
Ba2
Cl. B5, Downgraded to Ca; previously on 10/11/2004 Assigned
B2
Thornburg Mortgage Securities Trust 2004-4
Cl. II-A, Downgraded to Baa3; previously on 1/10/2005
Assigned Aaa
Cl. II-AX, Downgraded to Baa3; previously on
1/10/2005 Assigned Aaa
Cl. III-A, Downgraded to Aa2; previously on 1/10/2005
Assigned Aaa
Cl. III-AX, Downgraded to Aa2; previously on
1/10/2005 Assigned Aaa
Cl. IV-A, Downgraded to A1; previously on 1/10/2005
Assigned Aaa
Cl. IV-AX, Downgraded to A1; previously on 1/10/2005
Assigned Aaa
Cl. B-1, Downgraded to B2; previously on 1/10/2005
Assigned Aa2
Cl. B-2, Downgraded to Ca; previously on 1/10/2005
Assigned A2
Cl. B-3, Downgraded to Ca; previously on 1/10/2005
Assigned Baa2
Cl. B-4, Downgraded to Ca; previously on 1/10/2005
Assigned Ba2
Cl. B-5, Downgraded to Ca; previously on 1/10/2005
Assigned B2
Other methodologies and factors that may have been considered in the process
of rating this issue can also be found at www.moodys.com
in the Credit Policy & Methodologies directory.
A list of these actions including CUSIP identifiers may be found at:
Excel: http://www.moodys.com/cust/getdocumentByNotesDocId.asp?criteria=PBS_SF171614
A list of updated estimated pool losses is being updated on an ongoing
basis for the duration of this review period and may be found at:
Excel: http://www.moodys.com/cust/getdocumentByNotesDocId.asp?criteria=PBS_SF170400
For more information please see www.moodys.com.
New York
Debashish Chatterjee
VP - Senior Credit Officer
Structured Finance Group
Moody's Investors Service
JOURNALISTS: 212-553-0376
SUBSCRIBERS: 212-553-1653
New York
Juan Lopez
Senior Associate
Structured Finance Group
Moody's Investors Service
JOURNALISTS: 212-553-0376
SUBSCRIBERS: 212-553-1653
Moody's Downgrades $925 Million of Jumbo RMBS issued by Thornburg Mortgage Trust in 2002-2004