Welcome to The S-Curve
Now you will be able to receive the latest announcements, product updates, and our insights on the mortgage market in real time.
The name of the blog, the S-Curve, is a reflection of our logo and the central feature of our prepayment model. S-curves are seen in nature in many phenomenon, from population growth to prepayment and default models. Our first S-curve, in the early 1990s, used the arctangent function, then piece-wise linear functions, and evolved over time to be more complex and vary by FICO, loan size and LTV. This evolution encapsulates both the timeless nature of fundamental relationships and constant innovation to describe them better over time.
We hope you find the information useful and we look forward to your feedback.
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Agency LDM+ Available in Milliman M-PIRe™ProductsAndrew Davidson & Co., Inc (AD&Co) is thrilled to announce an expanding relationship with a Third-Party Vendor! AD&Co enjoys working with countless analytical providers to offer our clients seamless solutions and we would like to welcome Milliman M-PIRe™ to the team!
Milliman’s Integrate Solutions have supported AD&Co’s LoanDynamics Model (LDM) for many years. We've expanded on that relationship to include Milliman M-PIRe™ software. Milliman M-PIRe™ now supports AD&Co’s Agency+ LoanDynamics Model (Agency LDM+) to offer clients an industry-leading solution. AD&Co’s Agency LDM+ forecasts prepayments, delinquencies, defaults and loss probabilities, which are fed into Milliman M-PIRe™, a valuation and securitization software that produces advanced analytics of structured mortgage credit risk (CRT).
Today’s financial markets have taught us the importance of evaluating and managing financial risks. Milliman’s integration of AD&Co’s Agency LDM+ into the M-PIRe™ solution allows reinsurers and mortgage insurers to analyze CRT transactions using a multi-model framework when implementing risk and portfolio management strategies.
AD&Co would like to thank Milliman for their unparalleled support of our Agency LDM+ in the M-PIRe™ software. We truly appreciate their dedication to servicing mutual clients to ensure their success.
Interested in learning more about joint Milliman M-PIRe™ and Agency LDM+ solution? Please contact Jonathan Glowacki at jonathan.glowacki@milliman.com.
The S-Curve Archives
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ThoughtsRecently, aggregators have crossed market borders by issuing residential mortgage-backed securities (RMBS) backed by owner-occupied (OO), GSE-eligible conforming loans. Additionally, conforming mortgage loans have drawn investment interest from insurance companies fronted by aggregators and evaluated by third-party firms. These developments constitute historically rare disintermediations of the nearly monopsonist purchases of conforming loans by the GSEs.
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PodcastJoin Rob Landauer in a conversation with Abe Martin as they discuss his recent Pipeline article, "Modeling the Balance Behavior of HELOC Borrowers." In this episode, they highlight key points from the article as he shares insights into the draw component of HELOCs and provide an update on the beta rele
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News
We’re excited to announce a major addition to the Andrew Davidson & Co., Inc. (AD&Co) team. Industry leaders Kelli Sayres and Gene Park, known for building and scaling leading fixed-income analytics platforms, have joined AD&Co’s Business Development team.
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ThoughtsBuilding on our earlier research on expanded consumer attributes, AD&Co continues to explore how credit data contributes to modeling delinquency and prepayment risk, which are key drivers of mortgage servicing rights cash flows and valuation.
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EventsAndrew Davidson recently joined NFM Lending’s Greg Sher on the One On One podcast to discuss our recent white paper, “The Impact of Moving Away From the Tri-Merge Standard.”
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EventsAD&Co recently sponsored and attended SFVegas 2026 and Optimal Blue Summit 2026. This post shares the AD&Co team's unique perspectives and key takeaways from attending both conferences.
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NewsAD&Co US Mortgage High Yield Indices
The Federal Reserve Economic Data (FRED) portal, housed by the Federal Reserve Bank of St. Louis, has been publishing AD&Co’s CRT indices since 2019. These series posted under the overall name of “US Mortgage High-Yield” include total return rates and credit and option-adjusted spreads (crOAS) – a projected return’s spread over Treasury (in the past, Libor). These series are available going back to 2014-end and tiered by CRT initial supports.
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ThoughtsIn July 2025, the US Federal Housing Finance Agency (FHFA) announced that the government-sponsored entities (the Enterprises or GSEs), Fannie Mae and Freddie Mac, would permit lenders to choose between Classic FICO and VantageScore 4.0 credit score models for loans sold to the GSEs. FHFA also stated in a social media post that the tri-merge standard would be maintained for mortgage underwriting. Nevertheless, some mortgage industry stakeholders recommend moving away from the tri-merge standard for GSE mortgages in favor of a single or bi-merge report standard.
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News
As housing faces more climate threats that result in more losses, the insurance program that it sits on is teetering on the brink of collapse. Yet, the home insurance market has three distinct stakeholders that have competing priorities, and today, there is no motivation for a collaborative solution.
Understanding how to strengthen and protect the current structure requires looking at the cost burdens along with the risk for each of those parties.
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ThoughtsThere has been a flurry of activity in the mortgage markets since the 2018 passage of the Economic Growth, Regulatory Relief, and Consumer Protection Act. This act requires the Federal Housing Finance Agency (FHFA, now known as US Federal Housing) to validate and modernize the credit score models used in the housing finance system. It should be noted that so far, the discourse has been around mortgages sold to the Enterprises (Fannie Mae and Freddie Mac). Ginnie Mae has not provided any guidance on their plans to start using new credit score models.