DBRS Morningstar Confirms and Upgrades Ratings on Castell 2017-1 PLC

DBRS Ratings Limited (DBRS Morningstar) confirmed and upgraded the following ratings on the notes issued by Castell 2017-1 PLC (the Issuer):

-- Class A Notes confirmed at AAA (sf)
-- Class B Notes confirmed at AAA (sf)
-- Class C Notes upgraded to AAA (sf) from AA (low) (sf)
-- Class D Notes upgraded to A (high) (sf) from A (low) (sf)
-- Class E Notes upgraded to BBB (sf) from BBB (low) (sf)
-- Class F Notes upgraded to BB (high) (sf) from BB (sf)

The ratings address the timely payment of interest and ultimate payment of principal on or before the legal final maturity date in October 2044.

The rating actions follow an annual review of the transaction and are based on the following analytical considerations:

-- Portfolio performance, in terms of delinquencies, defaults, and losses.
-- Portfolio default rate (PD), loss given default (LGD), and expected loss assumptions on the remaining receivables.
-- Current available credit enhancement to the notes to cover the expected losses at their respective rating levels.
-- Current economic environment and an assessment of sustainable performance, as a result of the Coronavirus Disease (COVID-19) pandemic.

Castell 2017-1 PLC is a securitisation of second-lien mortgage loans originated in the UK by Optimum Credit Limited (OCL).

PORTFOLIO PERFORMANCE
As of April 2020, loans that were two to three months in arrears represented 0.7% of the outstanding portfolio balance and the 90+ delinquency ratio was 2.1%. As of April 2020, the cumulative loss ratio was 0.4%.

PORTFOLIO ASSUMPTIONS AND KEY DRIVERS
DBRS Morningstar conducted a loan-by-loan analysis of the remaining pool of receivables and has updated its base case PD and LGD assumptions to 12.0% and 29.8%, respectively.

CREDIT ENHANCEMENT
As of the April 2020 payment date, credit enhancement to the Class A, Class B, Class C, Class D, Class E and Class F notes was 68.4%, 54.9%, 38.6%, 26.4%, 16.3%, and 7.4%, up from 47.3%, 37.8%, 26.5%, 18.0%, 10.9%, and 4.7% in April 2019, respectively.

Credit enhancement to the rated notes is provided by subordination of junior classes, excluding the Class X Notes, which are repaid through available excess spread, and a general reserve fund.

The transaction benefits from a general reserve fund of GBP 4.3 million and a liquidity reserve fund of GBP 0.8 million. The general reserve fund covers senior fees as well as interest and principal (via the principal deficiency ledgers) on the rated notes. The liquidity reserve fund covers senior fees and interest on the Class A Notes and Class B Notes.

Citibank N.A., London Branch acts as the account bank for the transaction. Based on the DBRS Morningstar private rating of Citibank N.A., London Branch, the downgrade provisions outlined in the transaction documents, and other mitigating factors inherent in the transaction structure, DBRS Morningstar considers the risk arising from the exposure to the account bank to be consistent with the rating assigned to the Class A Notes, as described in DBRS Morningstar's "Legal Criteria for European Structured Finance Transactions" methodology.

NatWest Markets Plc acts as the swap counterparty for the transaction. DBRS Morningstar's public Long-Term Critical Obligations Rating of NatWest Markets Plc at “A” is above the First Rating Threshold as described in DBRS Morningstar's "Derivative Criteria for European Structured Finance Transactions" methodology.

DBRS Morningstar analysed the transaction structure in Intex DealMaker.

The Coronavirus Disease (COVID-19) and the resulting isolation measures have caused an economic contraction, leading to sharp increases in unemployment rates and income reductions for many borrowers. DBRS Morningstar anticipates that delinquencies may arise in the coming months for many RMBS transactions, some meaningfully. The ratings are based on additional analysis and adjustments to expected performance as a result of the global efforts to contain the spread of the coronavirus.

On 16 April 2020, the DBRS Morningstar Sovereign group published its outlook on the impact to key economic indicators for the 2020-22 time frame. These scenarios were updated on 1 June 2020. For details see the following commentaries: https://www.dbrsmorningstar.com/research/361867/global-macroeconomic-scenarios-june-update and https://www.dbrsmorningstar.com/research/359903/global-macroeconomic-scenarios-application-to-credit-ratings.

On 5 May 2020, DBRS Morningstar published a commentary outlining how the coronavirus crisis is likely to affect DBRS Morningstar-rated RMBS transactions in Europe. For more details, please see: https://www.dbrsmorningstar.com/research/360599/european-rmbs-transactions-risk-exposure-to-coronavirus-covid-19-effect and https://www.dbrsmorningstar.com/research/362712/european-structured-finance-covid-19-credit-risk-exposure-roadmap.

For more information regarding rating methodologies and Coronavirus Disease (COVID-19), please see the following DBRS Morningstar press release: https://www.dbrsmorningstar.com/research/357883.

For more information regarding structured finance rating methodologies and Coronavirus Disease (COVID-19), please see the following DBRS Morningstar press release: https://www.dbrsmorningstar.com/research/358308.

ESG CONSIDERATIONS
A description of how DBRS Morningstar considers ESG factors within the DBRS Morningstar analytical framework and its methodologies can be found at: https://www.dbrsmorningstar.com/research/357792.

Notes:
All figures are in British pound sterling unless otherwise noted.

The principal methodology applicable to the ratings is the “Master European Structured Finance Surveillance Methodology” (22 April 2020). DBRS Morningstar has applied the principal methodology consistently and conducted a review of the transaction in accordance with the principal methodology.

A review of the transaction legal documents was not conducted as the legal documents have remained unchanged since the most recent rating action.

Other methodologies referenced in this transaction are listed at the end of this press release. These may be found at: http://www.dbrsmorningstar.com/about/methodologies.

For a more detailed discussion of the sovereign risk impact on Structured Finance ratings, please refer to “Appendix C: The Impact of Sovereign Ratings on Other DBRS Credit Ratings” of the “Global Methodology for Rating Sovereign Governments” at: https://www.dbrsmorningstar.com/research/350410/global-methodology-for-rating-sovereign-governments.

The sources of data and information used for these ratings include investor reports provided by Citibank N.A., London Branch and loan-level data provided by OCL.

DBRS Morningstar did not rely upon third-party due diligence in order to conduct its analysis.

At the time of the initial rating, DBRS Morningstar was supplied with third-party assessments. However, this did not impact the rating analysis.

DBRS Morningstar considers the data and information available to it for the purposes of providing these ratings to be of satisfactory quality.

DBRS Morningstar does not audit or independently verify the data or information it receives in connection with the rating process.

The last rating action on this transaction took place on 4 July 2019, when DBRS Morningstar confirmed the ratings on the Class A and Class B Notes and upgraded the ratings on the Class C, Class D, Class E, and Class F Notes to AA (low) (sf), A (low) (sf), BBB (low) (sf), and BB (sf), respectively.

Information regarding DBRS Morningstar ratings, including definitions, policies, and methodologies is available at www.dbrsmorningstar.com.

To assess the impact of changing the transaction parameters on the rating, DBRS Morningstar considered the following stress scenarios as compared with the parameters used to determine the rating (the Base Case):

-- DBRS Morningstar expected a lifetime base case PD and LGD for the pool based on a review of the current assets. Adverse changes to asset performance may cause stresses to base case assumptions and therefore have a negative effect on credit ratings.
-- The base case PD and LGD of the current pool of loans for the Issuer are 12.0% and 29.8%, respectively.
-- The risk sensitivity overview below illustrates the ratings expected if the PD and LGD increase by a certain percentage over the base case assumption. For example, if the LGD increases by 50%, the rating of the Class A Notes would be expected to remain at AAA (sf), assuming no change in the PD. If the PD increases by 50%, the rating of the Class A Notes would be expected to remain at AAA (sf), assuming no change in the LGD. Furthermore, if both the PD and LGD increase by 50%, the rating of the Class A Notes would be expected to remain at AAA (sf).

Class A Notes Risk Sensitivity:
-- 25% increase in LGD, expected rating of AAA (sf)
-- 50% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD, expected rating of AAA (sf)
-- 50% increase in PD, expected rating of AAA (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of AAA (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of AAA (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of AAA (sf)

Class B Notes Risk Sensitivity:
-- 25% increase in LGD, expected rating of AAA (sf)
-- 50% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD, expected rating of AAA (sf)
-- 50% increase in PD, expected rating of AAA (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of AAA (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of AAA (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of AAA (sf)

Class C Notes Risk Sensitivity:
-- 25% increase in LGD, expected rating of AAA (sf)
-- 50% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD, expected rating of AA (high) (sf)
-- 50% increase in PD, expected rating of A (high) (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of AA (low) (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of A (high) (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of A (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of A (low) (sf)

Class D Notes Risk Sensitivity:
-- 25% increase in LGD, expected rating of A (high) (sf)
-- 50% increase in LGD, expected rating of A (low) (sf)
-- 25% increase in PD, expected rating of A (low) (sf)
-- 50% increase in PD, expected rating of BBB (high) (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of BBB (high) (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of BBB (high) (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of BBB (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of BBB (low) (sf)

Class E Notes Risk Sensitivity:
-- 25% increase in LGD, expected rating of BBB (sf)
-- 50% increase in LGD, expected rating of BBB (low) (sf)
-- 25% increase in PD, expected rating of BBB (sf)
-- 50% increase in PD, expected rating of BB (high) (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of BB (high) (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of BB (high) (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of BB (high) (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of BB (sf)

Class F Notes Risk Sensitivity:
-- 25% increase in LGD, expected rating of BB (high) (sf)
-- 50% increase in LGD, expected rating of BB (sf)
-- 25% increase in PD, expected rating of BB (high) (sf)
-- 50% increase in PD, expected rating of BB (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of BB (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of BB (low) (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of BB (low) (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of B (high) (sf)

For further information on DBRS Morningstar historical default rates published by the European Securities and Markets Authority (ESMA) in a central repository, see:
http://cerep.esma.europa.eu/cerep-web/statistics/defaults.xhtml.

Ratings assigned by DBRS Ratings Limited are subject to EU and U.S. regulations only.

Lead Analyst: Andrew Lynch, Vice President
Rating Committee Chair: Alfonso Candelas, Senior Vice President
Initial Rating Date: 21 June 2017

DBRS Ratings Limited
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Registered and incorporated under the laws of England and Wales: Company No. 7139960.

The rating methodologies used in the analysis of this transaction can be found at: http://www.dbrsmorningstar.com/about/methodologies.

-- Legal Criteria for European Structured Finance Transactions (11 September 2019),
https://www.dbrsmorningstar.com/research/350234/legal-criteria-for-european-structured-finance-transactions.
-- Master European Structured Finance Surveillance Methodology (22 April 2020),
https://www.dbrsmorningstar.com/research/359884/master-european-structured-finance-surveillance-methodology.
-- Operational Risk Assessment for European Structured Finance Servicers (28 February 2020), https://www.dbrsmorningstar.com/research/357429/operational-risk-assessment-for-european-structured-finance-servicers.
-- European RMBS Insight Methodology (2 April 2020) and European RMBS Insight Model 4.2.2.0, https://www.dbrsmorningstar.com/research/359194/dbrs-morningstar-publishes-updated-european-rmbs-insight-methodology
-- European RMBS Insight: U.K. Addendum (8 November 2019)
https://www.dbrsmorningstar.com/research/352573/european-rmbs-insight-uk-addendum.
-- Interest Rate Stresses for European Structured Finance Transactions (10 October 2019)
https://www.dbrsmorningstar.com/research/351557/interest-rate-stresses-for-european-structured-finance-transactions.
-- Derivative Criteria for European Structured Finance Transactions (26 September 2019)
https://www.dbrsmorningstar.com/research/350907/derivative-criteria-for-european-structured-finance-transactions.

A description of how DBRS Morningstar analyses structured finance transactions and how the methodologies are collectively applied can be found at http://www.dbrsmorningstar.com/research/278375.

For more information on this credit or on this industry, visit www.dbrsmorningstar.com or contact us at info@dbrsmorningstar.com.