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
  • Day of Service 2025

    Ashton Burnette

    Events

    The Andrew Davidson & Co., Inc. (AD&Co) DEI Day of Service 2025 provided the opportunity to have fun and support the greater NYC community at the same time. Hosted by the AD&Co DEI Committee, we first gathered at the AD&Co office to prepare backpacks for unhoused students in support of Volunteers of America® Greater New York’s Operation Backpack®. Essential school supplies are being distributed to Elementary, Middle, and High School students. This volunteer activity aligns closely with the AD&Co values of continuous learning and education, and I feel confident that this donation of school supplies will be impactful to these young students.

    Operation_Backpack_2025

    On to lunch, Jing Fong “has been a New York institution since 1978, specializing in dim sum and Cantonese cuisine.” But what is Dim Sum? As advised by blogger Justine Pang, “Dim sum is a Chinese cuisine, taken from the teahouse culture in Hong Kong and Guangdong Province; in which consist of small plates of Chinese food paired with a hot cup of tea, and accompanied with family and friends.” At one time, Jing Fong occupied a space with 800 seat capacity. The center of the table was filled with fresh, delicious food, and it spins on a lazy susan to allow for easy sharing.

    The last stop of the day was to the Museum of Chinese in America (MOCA). The museum specializes in collecting practical, everyday items that reflect ordinary life, and the magazine exhibit was especially interesting.
     

    The Herbalist

    The_Herbalist
    “In the early days of Chinese medicine in America, Chinese treatment for certain ailments was more effective than Western treatments and didn’t have side effects” - MOCA

     

    The Laundry

    The_Laundry
    Laundry businesses have historically provided a stable and reliable income for many Chinese immigrants who faced exclusion and racism from many other industries.

     

    The World of Magazines

    The_World_of_Magazines
    “Through magazine publishing, a vital form of mass media in the 1990s, Asian Americans editorialized issues central to their lives and depicted themselves in ways that were unimaginable before. Magazine Fever presents stories of Generation X magazines–how they were founded and sustained; how they captured the essence of multiculturalism and Generation X paradigms, and how they impacted the ways Asian American identity is understood today.” - MOCA

     

    It was great to experience Chinatown in Manhattan via food, history, and culture. I had the opportunity to purchase two books at MOCA and will follow both MOCA and Jing Fong on social media to continue to support future events!

Blog - Archives

The S-Curve Archives

  • Sanjeeban Chatterjee

    Thoughts

    Recently the Federal Housing Finance Agency (FHFA) announced some upcoming changes related to the use of new credit scores, FICO 10T and VantageScore 4.0 by Fannie Mae and Freddie Mac. “FHFA expects that implementation of FICO 10T and VantageScore 4.0 will be a multiyear effort. Once implemented, lenders will be required to deliver both FICO 10T and VantageScore 4.0 credit scores with each loan sold to the Enterprises”.[1] This announcement will impact the entire mortgage ecosystem.

  • Adam Marchuck

    Thoughts

    January is National Mentoring Month which is very appropriate since it coincides with the time when we typically set out our goals and intentions for the New Year. Organizations are embracing mentoring programs and these programs have indeed become a strategic imperative for many. There are many benefits to mentorship and it's easy enough to comprehend. The individuals involved in a mentoring relationship and the organizations that choose to sponsor a mentoring program all are likely to benefit.

  • Richard Cooperstein

    Thoughts

    Homeownership is the largest source of wealth accumulation and inter-generational wealth transfer for the working and middle class. However, the history of racial discrimination (it was actually legal to discriminate by race in housing until the Fair Housing Act of 1968), suggests that we have a continuing responsibility to ensure fair access to housing and housing finance. 

  • Andrew Davidson

    Thoughts

    Dear Friends,

    As Andrew Davidson & Co., Inc. (AD&Co) reaches its 30-year milestone, I reflect on two seemingly contradictory ideas:  Firms need experience to guide clients through difficult times but sometimes it is necessary to discard past practices to achieve breakthroughs. 

  • Connor Campbell

    Thoughts

    For many people, having accessible transportation (a car, for example) is necessary. Most U.S. people live in areas without adequate public transportation and require vehicles to access jobs, healthcare, and groceries.

  • Daniel Swanson

    Thoughts

    As interest rates rise and fewer loans with refinancing incentive remain, other factors are primed to play a larger role in determining prepayment speeds in the coming months (and perhaps years). Turnover, the rate at which people move, is the most cited of these factors.  In this blog post, we’ll consider two other potential drivers: curtailments, or partial prepayments, and mortgage payoffs that don’t involve taking out a new loan.

  • Richard Cooperstein

    Thoughts

    Summary

    In 2021, Andrew Davidson & Co. Inc. (AD&Co) proposed a benchmark cohort approach to setting Ability-to-Repay (ATR) Qualified Mortgages (QM) standards. Successful benchmarks based on data are model-free and transparent, and the cohorts must perform consistently in comparison to one another and across time. Our original work used data through the early stages of the pandemic when non-performing loan percentages skyrocketed.

  • Richard Cooperstein

    Thoughts

    How Lowering Capital Costs Affects Higher-Risk Loans

    Government-sponsored enterprises (or GSEs) are companies that provide guarantees and financing to originators through the mortgage secondary market. The size and resilience of the GSE secondary market maximizes diversification and liquidity which reduces financial risk and cost of capital. This benefit accrues to conforming borrowers through lower mortgage rates and resiliently available financing. 

  • Alex Levin

    Products

    The release of Andrew Davidson & Co., Inc.’s (AD&Co) new generation of financial engineering tools marks a shift to a new reality; when the traditional benchmark for MBS valuation, the LIBOR/ Swap yield curve, becomes unavailable. Our recent Product Release email informed our readers about the change. In short, our users can:

  • Richard Cooperstein

    Thoughts

    FHFA held a listening session for interested parties on its proposed rule on the GSE process for credit scores.  The objective is making mortgage underwriting and pricing more accurate and more fair while balancing practical implementation by firms in the mortgage ecosystem.  Along with many others, I had the opportunity to provide insights on this proposed rulemaking.