Fitch Rates $823.9MM Thornburg Mortgage Securities Trust Series 2007-5

NEW YORK--(BUSINESS WIRE)--Fitch rates Thornburg Mortgage Securities Trust (TMST) series 2007-5
residential mortgage pass-through certificates, as follows:

Group 1:

--$754,461,100 social classes 1A1, 1AX, 1A2, 2A1, 2AX, 3A1, 3A2, 3A3, 3A4,
3AX1, 3AX2 and A-R ('senior certificates') 'AAA';

--$11,725,000 social class B1 'AA';

--$5,865,000 social class B2 'A';

--$2,345,000 social class B3 'BBB'.

Group 2:

--$37,314,100 social classes 4A1, 4AX and 4AR ('senior certificates') 'AAA';

--$6,005,000 social class 4B1 'AA';

--$2,170,000 social class 4B2 'A';

--$1,150,000 social class 4B3 'BBB';

--$1,460,000 social class 4B4 'BB';

--$1,430,000 social class 4B5 'B'.

The 'AAA' evaluation on the senior certifications for grouping 1 reflects the
3.50% subordination provided by the 1.50% non-offered B1 class, the
0.75% non-offered B2 class, the 0.30% non-offered B3 class, the 0.45%
non-offered and non-rated B4 class, the 0.30% non-offered and non-rated
B5 social social social social social social class and the 0.20% non-offered and non-rated B6 class. Polecat
believes the above recognition sweetening will be adequate to back up
mortgager defaults, as well as bankruptcy, fraud, and particular jeopardy
losings in limited amounts. In addition, the evaluations reflect the quality
of the mortgage collateral, the strength of the legal and fiscal
structures, and the capablenesses of H. G. Wells Fargo Bank, N.A. (Well Fargo)
as maestro servicer (rated 'RMS1' by Fitch).

The 'AAA' evaluation on the senior certifications for grouping 2 reflects the
27.50% subordination provided by the 11.75% non-offered 4B1 class, the
4.25% non-offered 4B2 class, the 2.25% non-offered 4B3 class, the 2.86%
non-offered 4B4 class, the 2.80% non-offered 4B5 social social social social social social class and the 3.10%
non-offered and non-rated 4B6 class. Polecat believes the above recognition
sweetening will be adequate to back up mortgager defaults, as well as
bankruptcy, fraud, and particular jeopardy losings in limited amounts. In
addition, the evaluations reflect the quality of the mortgage collateral,
the strength of the legal and fiscal structures, and the capablenesses
of H. G. Wells Fargo Bank, N.A. (Well Fargo) as maestro servicer (rated 'RMS1'
by Fitch).

The mortgage pool for grouping 1 dwells primarily of 919 recently
originated, adjustable rate, conventional, first lien, one-to
four-family, residential mortgage loans, a significant bulk of which
have got original footing to adulthood of 30 years. As of the cut-off date, the
pool had an congeries principal balance of approximately $781,125,168. The norm loan balance is $850,735, and the leaden norm original
loan-to-value ratio (OLTV) for the mortgage loans in the pool is
approximately 68.33%. The leaden norm FICO recognition mark for the
pool is approximately 748. Cash-out and rate/term refinance loans
stand for 30.73% and 19.51% of the pool, respectively. Second and
investor-occupied homes business relationship for 22.21% and 12.60% of the pool,
respectively. The states that stand for the biggest geographical
concentration are Golden State (26.00%), New House Of York (12.65%) and Centennial State
(10.19%).

The mortgage pool for grouping 2 dwells primarily of 31 recently
originated, adjustable rate, conventional, first lien, one - to
four-family, residential mortgage loans, a significant amount of which
have got original footing to adulthood of 30 years. As of the cut-off date, the
pool had an congeries principal balance of approximately $51,115,114. The norm loan balance is $1,648,874, and the leaden norm
effectual loan-to-value ratio (OLTV) for the mortgage loans in the pool
is approximately 64.43%. The leaden norm FICO recognition mark for the
pool is approximately 725. Cash-out and rate/term refinance loans
stand for 55.00% and 15.22% of the pool, respectively. Second and
investor-occupied homes business relationship for 20.81% and 4.81% of the pool,
respectively. The states that stand for the biggest geographical
concentration are Golden State (34.27%), Nutmeg State (20.69%) and Grand Canyon State
(12.35%).

The mortgage loans in grouping 2 are adjustable-rate mortgages (ARMs) with
the possible to negatively amortize, commonly known as Option ARMs. The
Option arm borrowers have got four payment options: involvement only (IO),
minimal monthly payment (MMP), principal and involvement payment based on a
15-year amortization schedule, and principal and involvement payment based
on a 30- or 40-year amortization schedule. The loans may negatively
amortise if the borrower takes to do the MMP particularly in a
rise charge per unit environment. The Option weaponry in this pool are mostly indexed
to the 1 Year Libor rate.

None of the mortgage loans are 'high cost' loans as defined under any
local, state, or federal laws. For further information on Fitch's
evaluation criteria regarding predatory loaning legislation, see the fourth estate
release 'Fitch Revises Evaluation Criteria in Aftermath of Predatory Lending
Legislation,' dated May 1, 2003, available on the Polecat Ratings web land site
at .

Recognition Switzerland First Hub Of The Universe Mortgage Securities Corp. deposited the loans
in the trust, which issued the certificates, representing undivided
good ownership in the trust. For federal income taxation purposes,
elections will be made to handle the trust monetary fund as one or more than existent
estate mortgage investing conduits (REMICs). Sieur de LaSalle Bank, N.A. volition
move as Trustee and H. G. Wells Fargo Bank, N.A. volition move as securities
decision maker and maestro servicer for the trust.

Fitch's evaluation definitions and the footing of usage of such as evaluations are
available on the agency's public site, .
Published ratings, criteria and methodological analyses are available from this
site, at all times. Fitch's codification of conduct, confidentiality, struggles
of interest, affiliate firewall, conformity and other relevant policies
and processes are also available from the 'Code of Conduct' subdivision of
this site.