In the past two months, investors have seen outsized buyouts of delinquent loans from GNMA pools, leading to a significant uptick in prepayment speeds. Nearly all of these buyouts were driven by bank servicers, including Wells Fargo, US Bank, Truist, and Chase. GNMA buyout speeds in July’s report were the fastest, with Wells Fargo leading the charge on their seriously delinquent loans. The August report saw lower but still above-normal buyout activity. For September, we expect a further decline in bank buyout speeds, as the 60-day delinquent bucket for banks has declined from 6.6% just prior to the July report to 2.2% today.
During that same time, buyouts from non-banks were nearly non-existent. We note that the roll rate from 60-day delinquent to 90-day delinquent (buyout-eligible) is comparable between banks and non-banks. So buyout-eligible delinquencies for non-banks continue to build. That pipeline, coupled with the fact that non-banks service more than 75% of GNMA’s current balance, presents a substantial risk of future GNMA buyouts.
As discussed in previous posts, the differential in buyouts between banks and their non-bank counterparts is mainly due to bank servicers being able to warehouse delinquent loans until they reperform, modified or unmodified, or until they can otherwise dispose of the loan. Non-bank servicers typically do not have the balance sheet or funding to perform such buyouts in size. If these large non-bank servicers were to team with entities with access to cheap funding or were to set up funding facilities sponsored by investors, they could start to take advantage of the upside in re-securitization. The profits from securitizing reperforming loans is substantial, so non-bank servicers can afford to share the upside with yield-starved investors in return for access to funding. In this scenario, both parties could engage in a profitable trade.
Where do delinquencies stand for non-bank servicers? In the table below, we summarize the percentage of loans that have missed 3 or more payments for the top five non-bank servicers, by coupon and vintage. In this table, we show 90-day+ delinquencies, which are already eligible for buyout, as opposed to the 60 day delinquency analysis we performed for banks, where 60 day delinquencies feed the buyout-eligible bucket via a 75% to 80% roll-rate from 60-day to 90-day delinquent.
In this table, 2017-19 vintage GN2 3.5 through 4.5s show the largest overhang of non-bank delinquencies coupled with the largest percentage of non-bank servicing for the cohort.
We summarize delinquencies for the top five non-bank servicers because they presumably have a better chance at accessing liquidity from capital markets than smaller non-bank servicers. However, we observe significant build-up of 90-day+ delinquency across all non-bank servicers, which currently stands at 7.7% of non-bank UPB, much higher than the 6.6% bank-serviced 60-day delinquency in June.
Within the top five non-bank servicers, Penny Mac tended to have the largest buildup of 90-day+ delinquencies and Quicken tended to have the lowest but results varied from cohort to cohort. In the graph below, we show the 90+ delinquency pipeline for all GN2 30yr multi-lender pools.
While we cannot say for certain when (or if) the market will see significant buyout activity from non-bank servicers, seriously delinquent loans continue to build. This overhang of delinquent loans, coupled with the significant profits to be made from securitizing reperforming loans, poses the risk for a significant uptick in involuntary speeds in GN2 multi-lender pools.
 For this analysis, we focused on the roll rate for loans in 30yr GN2 Multi-lender pools vintage 2010 onward. See RiskSpan for analysis of other GNMA cohorts.
 Over the past two months, 77% of bank-serviced loans that were 60-days delinquent rolled to a buyout-eligible delinquency state compared to 75% for non-banks.
 This analysis was performed for loans that are securitized in 30yr GN2 multi-lender pools issued 2010 onward. The top five servicers include Lakeview, Penny Mac, Freedom, Quicken, and Nationstar (Mr. Cooper).
 Reperforming loans could include modifications or cures without modification. Even with a six-month waiting period for securitizing non-modified reperforming loans, the time-value of borrowing at current rates should prove only a mild hinderance to repurchases given the substantial profits on pooling reperforming loans.
There is justified concern within the investor community regarding the residential mortgage loans currently in forbearance and their ultimate resolution. Although most of the 4M loans in forbearance are in securities backed by the Federal Government (Fannie Mae, Freddie Mac or Ginnie Mae), approximately 400,000 loans currently in forbearance represent collateral that backs private-label residential mortgage-backed securities (PLS). The PLS market operates without clear, articulated standards for forbearance programs and lacks the reporting practices that exist in Agency markets. This leads to disparate practices for granting forbearance to borrowers and a broad range of investor reporting by different servicers. COVID-19 has highlighted the need for transparent, consistent reporting of forbearance data to investors to support a more efficient PLS market.
Inconsistent investor reporting leaves too much for interpretation. It creates investor angst while making it harder to understand the credit risk associated with underlying mortgage loans. RiskSpan performed an analysis of 2,542 PLS deals (U.S. only) for which loan-level foreclosure metrics are available. The data shows that approximately 78% of loans reported to be in forbearance were backing deals originated between 2005-2008 (“Legacy Bonds”). As you would expect, new issue PLS has a smaller percentage of loans reported to be in forbearance.
Not all loans in forbearance will perform the same and it is critical for investors to receive transparent reporting of underlying collateral within their PLS portfolio in forbearance. These are unchartered times and, unlike historic observations of borrowers requesting forbearance, many loans presently in forbearance are still current on their mortgage payments. In these cases, they have elected to join a forbearance program in case they need it at some future point. Improved forbearance reporting will help investors better understand if borrowers will eventually need to defer payments, modify loan terms, or default leading to foreclosure or sale of the property.
In practice, servicers have followed GSE guidance when conducting forbearance reviews and approval. However, without specific guidance, servicers are working with inconsistent policies and procedures developed on a company-by-company basis to support the COVID forbearance process. For example, borrowers can be forborne for 12-months according to FHFA guidance. Some servicers have elected to take a more conservative approach and are providing forbearance in 3-month increments with extensions possible once a borrower confirms they remain financially impacted by the COVID pandemic.
Servicers have the data that investors want to analyze. Inconsistent practices in the reporting of COVID forbearances by servicers and trustees has resulted in forbearance data being unavailable on certain transactions. This means investors are not able to get a clear picture of the financial health of borrowers in transactions. In some cases, trustees are not reporting forbearance information to investors which makes it nearly impossible to obtain a reliable credit assessment of the underlying collateral.
The PLS market has attempted to identify best practices for monthly loan-level reporting to properly assess the risk of loans where forbearance has been granted. Unfortunately, the current market crisis has highlighted that not all market participants have adopted the best practices and there are not clear advantages for issuers and servicers to provide clear, transparent forbearance reporting. At a minimum, RiskSpan recommends that the following forbearance data elements be reported by servicers for PLS transactions:
- Last Payment Date: The last contractual payment date for a loan (i.e. the loan’s “paid- through date”).
- Loss Mitigation Type: A code indicating the type of loss mitigation the servicer is pursuing with the borrower, loan, or property.
- Forbearance Plan Start Date: The start date when either a) no payment or b) a payment amount less than the contractual obligation has been granted to the borrower.
- Forbearance Plan Scheduled End Date: The date on which a Forbearance Plan is scheduled to end.
- Forbearance Exit – Reason Code: The reason provided by the borrower for exiting a forbearance plan.
- Forbearance Extension Requested: Flag indicating the borrower has requested one or more forbearance extensions.
- Repayment Plan Start Date: The start date for when a borrower has agreed to make monthly mortgage payments greater than the contractual installment in an effort to repay amounts due during a Forbearance Plan.
- Repayment Plan Scheduled End Date: The date at which a Repayment Plan is scheduled to end.
- Repayment Plan Violation Date: The date when the borrower ceased complying with the terms of a defined repayment plan.
The COVID pandemic has highlighted monthly reporting weaknesses by servicers in PLS transactions. Based on investor discussions, additional information is needed to accurately assess the financial health of the underlying collateral. Market participants should take the lessons learned from the current crisis to re-examine prior attempts to define monthly reporting best practices. This includes working with industry groups and regulators to implement consistent, transparent reporting policies and procedures that provide investors with improved forbearance data.
Having good Prepayment and Credit Models is critical in the analysis of Residential Mortgage-Backed Securities. Prepays and Defaults are the two biggest risk factors that traders, portfolio managers and originators have to deal with. Traditionally, regression-based Behavioral Models have been used to accurately predict human behavior. Since prepayments and defaults are not just complex human decisions but also competing risks, accurately modeling them has been challenging. With the exponential growth in computing power (GPUs, parallel processing), storage (Cloud), “Big Data” (tremendous amount of detailed historical data) and connectivity (high speed internet), Artificial Intelligence (AI) has gained significant importance over the last few years. Machine Learning (ML) is a subset of AI and Deep Learning (DL) is a further subset of ML. The diagram below illustrates this relationship:
Due to the technological advancements mentioned above, ML based prepayment and credit models are now a reality. They can achieve better predictive power than traditional models and can deal effectively with high-dimensionality (more input variables) and non-linear relationships. The major drawback which has kept them from being universally adopted is their “black box” nature which leads to validation and interpretation issues. Let’s do a quick comparison between traditional and ML models:
Within ML Models are two ways to train them:
- Supervised Learning (used for ML Prepay and Credit Models)
- Regression based
- Classification based
- Unsupervised Learning
Let’s compare the major differences between Supervised and Unsupervised Learning:
The large amounts of loan level time series data available for RMBS (agency and non-agency) lends itself well for the construction of ML models and early adopters have reported higher accuracy. Besides the obvious objections mentioned above (black box, lack of control, interpretation) ML models are also susceptible to overfitting (like all other models). Overfitting is when a model does very well on the training data but less well on unseen data (validation set). The model ends up “memorizing” the noise and outliers in the input data and is not able to generalize accurately. The non-parametric and non-linear nature of ML Models accentuates this problem. Several techniques have been developed to address this potential problem: reducing the complexity of decision trees, expanding the training dataset, adding weak learners, dropouts, regularization, reducing the training time, cross validation etc.. The interpretation problem is a bit more challenging since users demand both, predictive accuracy and some form of interpretability. Several interpretation methods are used currently, like PDP (Partial dependence plot), ALE (accumulated local effects), PFI (permutation feature importance) and ICE (individual conditional expectation) but each has its shortcomings. Some of the challenges with the interpretability methods are:
- Isolating Cause and Effect – This is not often possible with supervised ML models since they only exploit associations and do not explicitly model cause/effect relationships.
- Mistaking Correlation for Dependence – Independent variables have a correlation coefficient of zero but a zero correlation coefficient may not imply independence. The correlation coefficient only tracks linear correlations and the non-linear nature of the models makes this difficult.
- Feature interaction and dependence – An incorrect conclusion can be drawn about the features influence on the target when there are interactions and dependencies between them.
While ML based prepay and credit models offer better predictive accuracy and automatically capture feature interactions and non-linear effects, they are still a few years away from gaining widespread acceptance. A good use for such models, at this stage, would be to use them in conjunction with traditional models. They would be a good benchmark to test traditional models with.
Note: Some of the information on this post was obtained from publicly available sources on the internet. The author wishes to thank Lei Zhao and Du Tang of the modeling group for proofreading this post.
No such thing as a free lunch.
The world is full of free (and semi-free) datasets ripe for the picking. If it’s not going to cost you anything, why not supercharge your data and achieve clarity where once there was only darkness?
But is it really not going to cost you anything? What is the total cost of ownership for a public dataset, and what does it take to distill truly valuable insights from publicly available data? Setting aside the reliability of the public source (a topic for another blog post), free data is anything but free. Let us discuss both the power and the cost of working with public data.
To illustrate the point, we borrow from a classic RiskSpan example: anticipating losses to a portfolio of mortgage loans due to a hurricane—a salient example as we are in the early days of the 2020 hurricane season (and the National Oceanic and Atmospheric Administration (NOAA) predicts a busy one). In this example, you own a portfolio of loans and would like to understand the possible impacts to that portfolio (in terms of delinquencies, defaults, and losses) of a recent hurricane. You know this will likely require an external data source because you do not work for NOAA, your firm is new to owning loans in coastal areas, and you currently have no internal data for loans impacted by hurricanes.
Know the Data.
The first step in using external data is understanding your own data. This may seem like a simple task. But data, its source, its lineage, and its nuanced meaning can be difficult to communicate inside an organization. Unless you work with a dataset regularly (i.e., often), you should approach your own data as if it were provided by an external source. The goal is a full understanding of the data, the data’s meaning, and the data’s limitations, all of which should have a direct impact on the types of analysis you attempt.
Understanding the structure of your data and the limitations it puts on your analysis involves questions like:
- What objects does your data track?
- Do you have time series records for these objects?
- Do you only have the most recent record? The most recent 12 records?
- Do you have one record that tries to capture life-to-date information?
Understanding the meaning of each attribute captured in your data involves questions like:
- What attributes are we tracking?
- Which attributes are updated (monthly or quarterly) and which remain static?
- What are the nuances in our categorical variables? How exactly did we assign the zero-balance code?
- Is original balance the loan’s balance at mortgage origination, or the balance when we purchased the loan/pool?
- Do our loss numbers include forgone interest?
These same types of questions also apply to understanding external data sources, but the answers are not always as readily available. Depending on the quality and availability of the documentation for a public dataset, this exercise may be as simple as just reading the data dictionary, or as labor intensive as generating analytics for individual attributes, such as mean, standard deviation, mode, or even histograms, to attempt to derive an attribute’s meaning directly from the delivered data. This is the not-free part of “free” data, and skipping this step can have negative consequences for the quality of analysis you can perform later.
Returning to our example, we require at least two external data sets:
- where and when hurricanes have struck, and
- loan performance data for mortgages active in those areas at those times.
The obvious choice for loan performance data is the historical performance datasets from the GSEs (Fannie Mae and Freddie Mac). Providing monthly performance information and loss information for defaulted loans for a huge sample of mortgage loans over a 20-year period, these two datasets are perfect for our analysis. For hurricanes, some manual effort is required to extract date, severity, and location from NOAA maps like these (you could get really fancy and gather zip codes covered in the landfall area—which, by leaving out homes hundreds of miles away from expected landfall, would likely give you a much better view of what happens to loans actually impacted by a hurricane—but we will stick to state-level in this simple example).
Make new data your own.
So you’ve downloaded the historical datasets, you’ve read the data dictionaries cover-to-cover, you’ve studied historical NOAA maps, and you’ve interrogated your own data teams for the meaning of internal loan data. Now what? This is yet another cost of “free” data: after all your effort to understand and ingest the new data, all you have is another dataset. A clean, well-understood, well-documented (you’ve thoroughly documented it, haven’t you?) dataset, but a dataset nonetheless. Getting the insights you seek requires a separate effort to merge the old with the new. Let us look at a simplified flow for our hurricane example:
- Subset the GSE data for active loans in hurricane-related states in the month prior to landfall. Extract information for these loans for 12 months after landfall.
- Bucket the historical loans by the characteristics you use to bucket your own loans (LTV, FICO, delinquency status before landfall, etc.).
- Derive delinquency and loss information for the buckets for the 12 months after the hurricane.
- Apply the observed delinquency and loss information to your loan portfolio (bucketed using the same scheme you used for the historical loans).
And there you have it—not a model, but a grounded expectation of loan performance following a hurricane. You have stepped out of the darkness and into the data-driven light. And all using free (or “free”) data!
Hyperbole aside, nothing about our example analysis is easy, but it plainly illustrates the power and cost of publicly available data. The power is obvious in our example: without the external data, we have no basis for generating an expectation of losses after a hurricane. While we should be wary of the impacts of factors not captured by our datasets (like the amount and effectiveness of government intervention after each storm – which does vary widely), the historical precedent we find by averaging many storms can form the basis for a robust and defensible expectation. Even if your firm has had experience with loans in hurricane-impacted areas, expanding the sample size through this exercise bolsters confidence in the outcomes. Generally speaking, the use of public data can provide grounded expectations where there had been only anecdotes.
But this power does come at a price—a price that should be appreciated and factored into the decision whether to use external data in the first place. What is worse than not knowing what to expect after a hurricane? Having an expectation based on bad or misunderstood data. Failing to account for the effort required to ingest and use free data can lead to bad analysis and the temptation to cut corners. The effort required in our example is significant: the GSE data is huge, complicated, and will melt your laptop’s RAM if you are not careful. Turning NOAA PDF maps into usable data is not a trivial task, especially if you want to go deeper than the state level. Understanding your own data can be a challenge. Applying an appropriate bucketing to the loans can make or break the analysis. Not all public datasets present these same challenges, but all public datasets present costs. There simply is no such thing as a free lunch. The returns on free data frequently justify these costs. But they should be understood before unwittingly incurring them.