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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The Earth is Our Home: Let's Not Default on itEvents

Since 1970, April 22nd has been the annual day to appreciate our planet and recognize the importance of protecting it. But more and more, we realize that everyday needs to be Earth Day, and that we need to take better care of the place that gives us life. It’s becoming harder and harder to doubt the legitimacy of climate change, and how we as humans contribute it. At Andrew Davidson & Co., Inc. (AD&Co) we recognize the dramatic nature of climate change and how it effects our neighbors around the world. As experts in the mortgage market, we’re looking at the ways extreme weather, such as hurricanes, floods, drought, and melting glaciers, affects people’s homes, their way of life—and the availability and price of housing.
In our December 2020 Pipeline article we anticipated an increasing expectation on the need to measure and disclose exposure to climate change, and laid out some of the analytic challenges. We have focused on studying the existing research, reaching out to climate risk research firms, and understanding the landscape of what is available and what needs to be developed. As we explore different product ideas, we expect to reach out to our existing clients to help us understand better the ways we can continue to deliver leading-edge analytics in this space.
For additional information, check out this panel featuring AD&Co’s Eknath Belbase.
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Diversity Awareness Lifts all PeopleThoughts
To seek "causes" of poverty in this way is to enter an intellectual dead end because poverty has no causes. Only prosperity has causes. – Jane Jacobs, Activist and Author
Here at Andrew Davidson & Co., Inc. (AD&Co) we have been aware since our founding in 1992 that diversity of all kinds makes for a more interesting culture, a better exchange of ideas, and ultimately better products and services. However, for all of us, globally and in the U.S., there is still a long way to go. We are focused on increasing our sensitivity to diversity and unconscious bias and have made diversity outreach in recruiting, mentorship, vendors, charitable giving—indeed, in every aspect of our business a priority. We have been focused on the fact that every person deserves an equitable life. Our guiding principle is that we are all people and we all deserve to be treated equally.
This is especially relevant to issues of housing as AD&Co’s Richard Cooperstein has addressed in the article he co-authored with Ken Fears from the National Association of Realtors (NARS) and Susan Wachter of the Wharton School for Business, University of Pennsylvania, Government-Sponsored Enterprises: Their Viability as Public Utilities published in the journal “Housing Policy Debate,” Volume 31, 2021 - Issue 1: The Mortgage Market in the Time of COVID / Smart Cities, Housing, and Community Development Policy.
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Listen To Freddie Mac's Interview With Andy Davidson On Their Inaugural Single-family PodcastEvents
CRTcast, a new podcast series under Freddie Mac’s Home Starts Here programming, focuses on credit risk transfer (CRT) and it’s three spokes: securities, (re)insurance and mortgage insurance. Freddie Mac leadership together with CRT industry experts cover current and relevant topics.
In the inaugural episode, Single-Family CRT Vice President Mike Reynolds sits down with Andrew Davidson & Co., Inc, (AD&Co) founder Andy Davidson to talk all things risk intelligence, including planting the seeds of a GSE CRT market in 2010; and connecting with Freddie Mac to launch the first GSE CRT securities transaction in 2013.
Click here to listen to the podcast.
About Freddie Mac Single-Family Credit Risk Transfer
Freddie Mac’s Single-Family CRT programs transfer credit risk away from U.S. taxpayers to global private capital via securities and (re)insurance policies. The GSE Single-Family CRT market was founded when Freddie Mac issued the first STACR® (Structured Agency Credit Risk) notes in July 2013. In November 2013, ACIS® (Agency Credit Insurance Structure was introduced. Today, CRT serves as the primary source of private capital investment in residential mortgage credit. For specific STACR and ACIS transaction data, please visit Clarity, Freddie Mac’s CRT data intelligence portal.
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Richard Cooperstein named co-chair of the Structured Finance Association’s Regulatory Capital & Liquidity CommitteeNews
We are proud to announce that Richard Cooperstein has accepted the position of co-chair of the Structured Finance Association’s (SFA) Regulatory Capital & Liquidity committee.
“I am very pleased to be chosen to co-lead SFA’s Committee that is focused on rationalizing risk transfer for federally-connected institutions. Aligning the regulation of risk transfer with the economics can improve capital efficiency, lower borrowing costs and reduce taxpayer risk.” - Richard Cooperstein
SFA plays an essential role in Structured Finance by bringing thought leaders together to collaborate on ways to respond to timely events affecting the industry, finance and our world.
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Andrew Davidson & Co., Inc. Celebrates Lunar New YearNews
Today we acknowledge the Year of the Ox. Happy Lunar New Year! We stand in solidarity with the Asian community against all violence and racism. Here’s to a year of peace, health and prosperity.

The S-Curve Archives
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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.
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EventsAndrew Davidson & Co., Inc (AD&Co) proudly sponsored IMN’s 11th Annual Mortgage Servicing Rights (MSR) Forum by Informa at the New York Hilton Midtown. Senior modeler Daniel Swanson joined the “Managing Delinquencies & Forbearance Value” panel in discussing how servicers are adapting to today’s market and the evolving delinquency trends.
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PodcastTune in to our fourth episode of AD&Conversations with Kevin Lin and Eknath Belbase, our product lead for our Climate model. In this episode, they discuss the new Climate Impact Suite (CIS) pilot project, and Belbase outlines several challenges the team is navigating, including: