Prepayment Analytics Archives

The Problem

The Client was shopping around for an analytics and risk platform to be used by both the trading desk and risk managers.

RiskSpan Edge Platform enabled highly scalable analytics and risk modeling providing visibility and control to address investment analysis, risk surveillance, stress testing and compliance requirements.

The Solution

Initially, the solution was intended for both the trading desk (as pre-trade analysis) as well as risk management (running scenarios on the existing portfolio). Ultimately, the system was used exclusively by risk management and used heavily by mid-level risk management.

Cloud Native Risk Service

We have transformed portfolio risk analytics through distributed cloud computing. Our optimized infrastructure powers risk and scenario analytics at speed and cost never before possible in the industry.

Perform advanced portfolio analysis to achieve risk oversight and regulatory compliance with confidence. Access reliable results with cloud-native interactive dashboards that satisfy investors, regulators, and clients.

Two Flexible Options

Fund Subscriber Service + Managed Service

Each deployment option includes on-demand analytics, standard batch and over-night processing or a hybrid model to suit your specific business needs. Our team will work with customers to customize deployment and delivery formats, including investor-specific reporting requirements.

Easy Integration + Delivery

Access Your Risk

Accessing the results of your risk run is easy via several different supported delivery channels. We can accommodate your specific needs – whether you’re a new hedge fund, fund-of-funds, bank or other Enterprise-scale customer.

“We feel the integration of RiskSpan into our toolkit will enhance portfolio management’s trading capabilities as well as increase the efficiency and scalability of the downstream RMBS analysis processes. We found RiskSpan’s offering to be user-friendly, providing a strong integration of market / vendor data backed by a knowledgeable and responsive support team.”

The Deliverables

Enabled running various HPI scenarios and tweaked the credit model knobs to change the default curve, running a portfolio of a couple hundred non-agency RMBS

Scaling the processing power up/down via the cloud, and they would iterate through runs, changing conditions until they got the risk numbers they needed

Simplified integration into their risk reporting system, external to RiskSpan

Most asset-liability management (ALM) models contain an embedded prepayment model for residential mortgage loans. To gauge their accuracy, prepayment modelers typically run a back-test comparing model projections to the actual prepayment rates observed. A standard test is to run a portfolio of loans as of a year ago using the actual interest rates experienced during this time as well as any additional economic factors used by the model such as home price appreciation or the unemployment rate. This methodology isolates the model’s ability to estimate voluntary payoffs from its ability to forecast the economic variables.

The graph below was produced from such a back-test. The residential mortgage loans in the bank’s portfolio as of 10/31/2016 were run through the ALM model (projections) and compared with the observed speeds (actuals). It is apparent that the model did not do a particularly good job forecasting the actual CPRs, as the mean absolute error is 5.0%. Prepayment model validators typically prefer to see mean absolute error rates no higher than 1 to 2%.

Does this mean there is something unique with the bank’s loan portfolio or servicing practices that would cause prepays to deviate from expectations, or does the prepayment model require calibration?

Dissecting the Problem

One strategy is to compare the bank’s prepayment experience to that of the market (see below). The “market” is the universe of comparable loans, in this case residential, conventional loans. This assessment should indicate whether the bank’s portfolio is unique or if it behaves similar to the market. Although this comparison looks better, there are still some material differences, especially at the beginning and end of the time series.

Examining the portfolio composition reveals a number of differences which could be the source of the discrepancy. For example:

Larger-balance loans have a greater refinance incentive.
California loans historically prepay faster than the rest of the country, while New York loans are historically slower.
Broker and correspondent loans typically pay faster than retail originations.

To compensate, the next step is to adjust the market portfolio to more closely mirror the attributes of the bank’s portfolio. Fine-tuning the “market” so that it better aligns with the bank’s channel and geographic breakout, as well as its larger average loan size, results in the following adjusted prepayment speeds.

Conclusion

Prepayments for the bank’s mortgage portfolio track the market speeds reasonably well with no adjustments. Compensating for the differences in composition related to channel, geography, and loan size tracks even better and results in a mean absolute error of only 1.1%. This indicates that there is nothing unique or idiosyncratic with the bank’s portfolio that would cause projections from a market-based prepayment model to deviate significantly from the observed speeds. Consequently, the ALM prepayment model likely needs adjustments to its tuning parameters to better capture the current environment.

Case Study: RS Edge – Analytics and Risk

The Client

Large Life Insurance Company – Investment Group

The Problem

The Solution

Cloud Native Risk Service

Two Flexible Options

Fund Subscriber Service + Managed Service

Easy Integration + Delivery

Access Your Risk

The Deliverables

Risk-as-a-Service – Transforming Portfolio Market Risk Analytics

Back-Testing: Using RS Edge to Validate a Prepayment Model

Dissecting the Problem

Company

Products

Security & Compliance