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.
-
Andrew Davidson & Co., Inc. Celebrates Pride MonthEvents

We at Andrew Davidson & Co., Inc. (AD&Co) are once again thrilled to celebrate Pride Month, especially the contributions of LGBTQ professionals in the field of finance including affordable housing policy and the GSEs. This year, in addition to celebrating, we are also paying increased attention to the challenges that LGBTQ individuals face, particularly around issues of housing. Our pride in our LGBTQ staff and community sits alongside our concern about discriminatory lending practices, including in mortgages. As of February 2021, for the first time, lesbian, gay, bisexual, transgender, queer, and questioning (LGBTQ) Americans will be protected from housing discrimination under the Fair Housing Act.
We have also had our eyes opened to youth homelessness. LGBTQ people make up 40% of the homeless youth population in the country: Their risk of homelessness is 120% of the general population.
We at AD&Co are committed to change. Here’s to Pride!
-
U.S. Mortgage High Yield Indexes From Andrew Davidson & Co Added to St. Louis Fed's FRED DatabaseNews
For several years, AD&Co has tracked the total rate of return (TRR) performance of the GSE CAS and STACR CRT in its U.S. Mortgage High-Yield Indices. The AD&Co Mid-Tier index constitutes a broad market measure of the TRR performance of GSE CRT. The related sub-indices segregate the CRT market into 4 index Tiers by attachment point, reflective of the credit exposure of the various classes of underlying CRT ranging from B to M1.
We are pleased to announce that the historical time series for these indices is now publicly available on the St. Louis Federal Reserve's FRED database, along with the credit-adjusted OAS (CrOAS) for each series. FRED is host to almost 800,000 data series from more than 100 sources. The indices published on FRED can be viewed here. Detailed performance analysis related to the index is available on a monthly basis at through AD&Co.
For more information please contact Rob Landauer at 212-274-9075, email Rob at rob@ad-co.com or visit www.ad-co.com.

Disclaimer: The AD&Co U.S. Mortgage High-Yield Index serves as an informational index and is not for commercial-use purposes. The Index’s accuracy, completeness, timeliness, and suitability for any purpose are not guaranteed. The Index does not constitute (1) investment, legal, accounting, tax, or other professional advice or (2) any recommendation or solicitation to purchase, hold, sell, or otherwise deal in any investment. This Index has been prepared for general informational purposes, without consideration of the circumstances or objectives of any particular investor. Any reliance on the Index is at the reader’s sole risk. All investment is subject to numerous risks, known and unknown. Past performance is no guarantee of future results. For investment advice, seek a qualified investment professional. Not for redistribution without permission. Note: An affiliate of Andrew Davidson & Co., Inc. engages in trading activities in investments that may be the same or similar to those featured in the Index.
-
Asian Pacific Heritage MonthEvents

We at Andrew Davidson & Co., Inc. (AD&Co) stand in solidarity with the Asian community and speak out against the xenophobic ignorance that has led to increased racist attacks against Asians. We protest against these hate crimes. This is a time to celebrate the richness that we have gained from the diversity of the Asian culture. We pledge to support the heritage that is part of what makes us American.
-
Mental Health Awareness MonthEvents
What does it mean to be mentally healthy? The answer is different for everyone. With all the extra anxiety that many of us have experienced since 2020, whether from uncertainty about COVID-19 or from other experiences that may be new to us, it’s important to acknowledge that it’s alright to not feel alright. Fortunately, there are numerous resources that are available locally, nationally, and in some cases through your workplace or benefits package. We might start by finding out what makes us feel better. For some, it is a brisk walk outside, a yoga class, talking to a friend, or finding a sympathetic therapist. The possibilities are endless. Let’s take this month to think about what WE need.
-
Introducing AutoLDM—A New Way to Analyze Auto LoansProducts
Today marks the publication of Chris Widman's Quantitative Perspective, a comprehensive article on the newest member of our LoanDynamics suite, the Auto LoanDynamics Model. Auto LDM will be integrated into vendor systems and AD&Co tools, allowing users to perform analysis on auto loan and ABS positions. Applications include economic scenario analysis to examine the impact of unemployment scenarios or rates on defaults, losses and prepayments, stress testing for CCAR/CECL, valuation and risk measurement.
The article provides an overview of the auto loan market, discusses the underlying data used for estimation, our model architecture, and contains sections on delinquency, seasonality, unemployment and severity determinants. We look forward to your feedback – please reach out to us at support@ad-co.com if you are interested in more details or a trial.
-Eknath Belbase
The S-Curve Archives
-
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:
-
Podcast
Andrew Davidson was invited to speak on Equifax's Market Pulse Podcast titled, "Driving Efficiency and Resilience in the Mortgage Industry" live at the 2025 MBA Annual Convention in Las Vegas.
Andy explains how variations in data files can distort risk assessment, creating a dual risk for lenders: extending credit to borrowers more likely to default while overcharging customers whose risk is overstated.
-
ThoughtsOur latest Policy Perspective written by Richard Cooperstein offers an analysis of the U.S. housing and mortgage finance markets, focusing on key trends and forward-looking risks. While housing markets are not fully efficient, they do respond to economic imbalances which create opportunities and vulnerabilities. This article explores how demographic shifts, credit access, interest rates, and climate risks shape both housing demand and supply.
Key findings include:
-
PodcastJoin Kevin Lin in a conversation with Richard Cooperstein as they dive into Kinetics, AD&Co's modular platform designed to deliver the full power of our models and analytics; with the flexibility to license only the tools you need.
-
ThoughtsThe latest Policy Perspectives paper “Competing Claims in Privatization of Fannie Mae and Freddie Mac” is now available!
Nearly 20 years ago, on September 6, 2008, the GSEs, Fannie Mae and Freddie Mac entered conservatorship. Since that time there have been many proposals to restructure, eliminate or release the GSEs. Once again there is talk about the privatization of Fannie Mae and Freddie Mac.
-
ThoughtsAD&Co held our annual employee meeting in Detroit, Michigan. In addition to gathering everyone in person to socialize and strategize, we use these annual meetings to learn about different cities, especially with regard to housing market dynamics.
We chose Detroit because the oft-maligned city is undergoing a significant renaissance, and we wanted to explore the area and learn how housing may have played a role in both Detroit’s decline and rebirth.
-
ProductsAndrew Davidson & Co., Inc (AD&Co) is pleased to announce the beta release of MARS+, the next generation of Mortgage Analysis & Reporting System (MARS), which has been in use since 2008 for performance reporting of AD&Co models. MARS+ aims to provide enhanced and advanced capabilities and features for mortgage analysis and reporting.
The new enhancements of MARS+ include:
-
EventsSeveral AD&Co employees attended SFVegas 2025. This post shares their unique perspectives from attending the conference and key takeaways from the sessions.
-
ThoughtsWe’re excited to announce our latest Quantitative Perspectives providing in-depth insights into current market trends and advanced valuation techniques. This publication offers valuable information for mortgage market participants and those involved in credit risk transfer transactions.
-
PodcastTune in to Laura Silberg's interview with Andrew Davidson, Eknath Belbase and Alex Levin as they discuss their latest Quantitative Perspectives, our independent commentary series, titled