Moody's Investors Service has downgraded the ratings of six tranches backed by Prime Jumbo RMBS loans, issued by miscellaneous issuers.
Complete rating actions are as follows:
Issuer: Citicorp Mortgage Securities Trust, Series 2007-6
Cl. IA-IO Certificate, Downgraded to B1 (sf); previously on May 19, 2010 Downgraded to Ba3 (sf)
Issuer: RFMSI Series 2005-S4 Trust
Cl. A-V Certificate, Downgraded to Caa1 (sf); previously on Jul 19, 2011 Confirmed at B1 (sf)
Issuer: Thornburg Mortgage Securities Trust 2007-1
Cl. A-3A Certificate, Downgraded to Caa1 (sf); previously on Jul 11, 2013 Downgraded to B3 (sf)
Cl. A-X Certificate, Downgraded to Caa2 (sf); previously on Jul 11, 2013 Downgraded to Caa1 (sf)
Issuer: Thornburg Mortgage Securities Trust 2007-2
Cl. A-3A Certificate, Downgraded to Caa1 (sf); previously on May 9, 2014 Affirmed B1 (sf)
Cl. A-X Certificate, Downgraded to Caa2 (sf); previously on May 9, 2014 Affirmed Caa1 (sf)
RATINGS RATIONALE
The actions are a result of the recent performance of the underlying pools and reflect Moody's updated loss expectations on the pools. The ratings downgraded are due to the weaker performance of the underlying collateral and the erosion of enhancement available to the bonds.
Factors that would lead to an upgrade or downgrade of the rating:
Ratings in the US RMBS sector remain exposed to the high level of macroeconomic uncertainty, and in particular the unemployment rate. The unemployment rate fell to 5.0% in October 2015 from 5.7% in October 2014. Moody's forecasts an unemployment central range of 5% to 6% for the 2015 year. Deviations from this central scenario could lead to rating actions in the sector.
House prices are another key driver of US RMBS performance. Moody's expects house prices to continue to rise in 2015. Lower increases than Moody's expects or decreases could lead to negative rating actions.
Finally, performance of RMBS continues to remain highly dependent on servicer procedures. Any change resulting from servicing transfers or other policy or regulatory change can impact the performance of these transactions.
A list of these actions including CUSIP identifiers may be found at:
Excel: http://www.moodys.com/viewresearchdoc.aspx?docid=PBS_SF421951
A list of updated estimated pool losses and bond recoveries is being posted on an ongoing basis for the duration of this review period and may be found at:
Excel: http://www.moodys.com/viewresearchdoc.aspx?docid=PBS_SF243269


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