DBRS Morningstar Confirms Ratings on Castell 2018-1 PLC

DBRS Ratings Limited (DBRS Morningstar) confirmed the following ratings on the notes issued by Castell 2018-1 PLC (the Issuer):

-- Class A at AAA (sf)
-- Class B at AA (low) (sf)
-- Class C at A (low) (sf)
-- Class D at BBB (high) (sf)
-- Class E at BB (high) (sf)
-- Class F at B (low) (sf)

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

The confirmations 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.

Castell 2018-1 PLC is a securitisation of second-lien mortgage loans originated by Optimum Credit Limited (Optimum Credit) in the United Kingdom.

PORTFOLIO PERFORMANCE
As of July 2019, two- to three-month arrears represented 0.3% of the outstanding portfolio balance and the 90+ delinquency ratio was 0.6%. As of July 2019, the cumulative loss ratio was zero.

PORTFOLIO ASSUMPTIONS
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 9.3% and 40.1% respectively.

CREDIT ENHANCEMENT
As of the July 2019 payment date, credit enhancement to the Class A, B, C, D, E and F notes was 35.0%, 27.2%, 20.0%, 15.1%, 11.5% and 7.5%, respectively, up from 28.5%, 21.7%, 15.4%, 11.0%, 7.8% and 7.3%, respectively, at the time of DBRS Morningstar’s initial rating.

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 7.7 million and a liquidity reserve fund of GBP 3.6 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.

The transaction structure was analysed in Intex DealMaker.

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”.

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 on www.dbrs.com at: http://www.dbrs.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.dbrs.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 Optimum Credit.

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 1 November 2018, when DBRS Morningstar finalised its provisional ratings on the notes.

The lead analyst responsibilities for this transaction have been transferred to Andrew Lynch.

Information regarding DBRS Morningstar ratings, including definitions, policies and methodologies is available at www.dbrs.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 9.3% and 40.1%, 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 fall to AA (low) (sf), assuming no change in the PD. If the PD increases by 50%, the rating of the Class A notes would be expected to fall to A (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 fall to BBB (high) (sf).

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

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

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

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

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

Class F Risk Sensitivity:
-- 25% increase in LGD, expected rating of B (low) (sf)
-- 50% increase in LGD, expected rating of B (low) (sf)
-- 25% increase in PD, expected rating of B (low) (sf)
-- 50% increase in PD, expected rating of B (low) (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of B (low) (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of B (low) (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of B (low) (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of B (low) (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 US regulations only.

Lead Analyst: Andrew Lynch, Assistant Vice President
Rating Committee Chair: Alfonso Candelas, Senior Vice President
Initial Rating Date: 8 October 2018

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.dbrs.com/about/methodologies.

-- Legal Criteria for European Structured Finance Transactions
-- Master European Structured Finance Surveillance Methodology
-- Operational Risk Assessment for European Structured Finance Servicers
-- European RMBS Insight Methodology
-- European RMBS Insight: U.K. Addendum
-- Interest Rate Stresses for European Structured Finance Transactions
-- 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.dbrs.com/research/278375.

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