The S-Curve

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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Blog - Latest
  • Impressions from SFVegas and OB Summit 2026

    Eknath Belbase, Daniel Swanson, Yvonne Chen

    Events

    AD&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.

    The New Non-Agency Model, Real Estate Exposure to Climate-Related Hazards & Escrow Analysis (Eknath Belbase)

    Daniel and I recorded a Exchange Live: Tech Odyssey podcast on Kinetics and the upcoming release of LDM v4.0. The 30-minute audio and accompanying slides are available on demand. We focused on DSCR/prepay penalty, along with the addition of climate.

    My panel on climate risk and property values went well – this year the focus shifted a bit to resilience, and the opportunity to reduce the rate of insurance increases by putting money up front into strengthening homes. Several states are funding the initial outlay required in pilot programs as part of insurance affordability initiatives (including Deep South states). David Zhang of MSCI started off the discussion with a tally of damages from physical risk sorted into quintiles of cost (measured against home value). The top quintile is already at a mean of 55bps per year of loss (these are only losses from weather events of scale and insurance needs to include costs such as fires starting from appliances or flooding from sewer back-ups).

    Finally, we learned that Cotality has a database of property tax histories on all U.S. single-family homes and is working on an approach to forecast taxes going forward, so our vision of a full escrow-conditioned HPA and LDM is within reach.

    Contact us for more information on LDM v4.0.

    Key Takeaways (Daniel Swanson)

    It was great to see so many familiar faces and to see the conference booming (though also a bit foreboding – the last time it was so packed, there was a crisis shortly thereafter). Here are a few key takeaways I had from talking to different people.

    Non-QM

    • There is a lot of interest in non-QM from many sophisticated participants
    • Analyzing new loans is complicated and most people are not taking advantage of all the information in the deals

    Climate

    • State-level behavior is changing, particularly FL payups, perhaps due to taxes and insurance (that link is hard to prove)
    • Servicers are starting to care about T+I for several different reasons (escrow float=positive, delinquency risk=negative)

    Credit Scores

    • Participants are mostly worried about disruption to their process when thinking about credit scores rather than performance

    AI

    • Everyone is thinking about AI, whether they are talking about it or not (and there are plenty of people talking about it)

    How AD&Co and Optimal Blue Are Transforming Pipeline Risk Management for Loan Originators (Yvonne Chen)

    At the Optimal Blue Summit 2026, we connected with loan originators and our alliance partners at Optimal Blue to discuss the evolving challenges in the mortgage origination sector. The conversations and conference sessions reinforced the patterns we've been seeing: Origination is a thin margin business, and originators must carefully manage the uncertainty and financial risks from locking rates at the beginning of the application process through to loan sale. Lenders manage their pipelines across agency and non-agency loan products while simultaneously borrowing closing funds and hedging to protect their profit margins – all while contending with interest rate volatility, fallout risk, basis risk in non-QM products, and borrower renegotiation. Fallout rates have climbed in recent years as borrower behavior shifts and competition intensifies in a low-volume market, making accurate pipeline risk management more critical than ever. Optimal Blue and AD&Co see the persistent need for the kind of sophisticated analytics that we can provide to help lenders stay ahead of these challenges.

    AD&Co was featured on a panel where Matteo Caracciolo-King had the chance to present a first look at our insights on consumer behavior in the application process based on Optimal Blue’s national application data set. Originators were keenly interested in forecasting application stage transition probabilities, which vary over time and across interest rates, as well as the kind of financial risk metrics that AD&Co can provide. The conference confirmed our view that, as pipeline hedging grows more complex, particularly with a fast-growing non-agency market, we see a meaningful opportunity to help originators strengthen their risk management through advanced analytics integrated into the Optimal Blue platform they already rely on.

Blog - Archives

The S-Curve Archives

  • Richard Cooperstein

    Thoughts

    In the spring of 2019, National Association of Realtors® (NAR), together with financial-market experts Susan Wachter (Wharton) and Richard Cooperstein (Andrew Davidson & Co., Inc.)  proposed completing the transition of Fannie Mae and Freddie Mac (Enterprises) into market utilities in a publication entitled “A Vision for Enduring Housing Finance Reform.” This work builds on Richard Cooperstein and Andrew Davidson’s 2017 paper

  • AD&Co Marketing Team

    News

    We proudly launched our new website on November 13th. As you familiarize yourself with the new look of ad-co.com, you will come to know the many new offerings we provide. Along with the new website, we have organized our products as a menu of models and applications for a wide range of investor appetites. Let us review the menu of our product offerings.

  • Tom Parrent

    Thoughts

    Separating signal from noise is at the heart of what we do at AD&Co. One of the key tools we utilize for that purpose is a sophisticated set of model performance trigger reports. These monthly reports not only alert us to model drift but also point to possible causes for the drift.

  • AD&Co Marketing Team

    News

    Andrew Davidson & Co., Inc. (AD&Co), is proud to support Fite Analytics’ innovative cloud-native Mortgage-Backed Securities Analytics Service. The Fite Analytics solution incorporates AD&Co’s LoanDynamics models that provide forecasts of voluntary prepayments, defaults and losses that drive risk analytics across the mortgage-backed securities market with comprehensive coverage.

  • Eric Limjoco

    News

    We are thrilled to announce that Andrew Davidson & Co., Inc. has launched a new look for ad-co.com. Some of the exciting new features of this site include:

    • A dynamic homepage highlighting the firm’s latest innovations, AD&Co client benefits, announcements, and Diversity, Equity and Inclusion efforts.