Same Rates, Different Speeds: Rethinking Prepayment Risk in Agency and Non-Agency MBS

Kelli Sayres joined the Business Development team at Andrew Davidson & Co., Inc. in 2026.

Prior to joining AD&Co, Kelli spent more than two decades at PolyPaths, a fixed-income software provider specializing in mortgage and option-adjusted analytics.  Her first role there was to write the user manual, after which she worked her way up from client support associate to product manager to senior managing director of the company, guiding both day-to-day operations and long-term strategic vision.  Throughout the years, she has donned many hats, including financial modeling, quantitative and technical support, quality assurance testing, documentation, product design, model validation, sales, and marketing.  After PolyPaths was acquired by Numerix in 2023, Kelli served as Head of Product, developing a fixed-income roadmap and facilitating the integration of PolyPaths’ people, processes, and product into the larger firm.

Kelli holds an M.S. in Computational Finance from Carnegie Mellon University, along with a B.S. in Mathematics and a B.A. in History from Stanford University.

Gene Park joined the Business Development team at Andrew Davidson & Co., Inc. in 2026.

Prior to AD&Co, Gene spent over 20 years at PolyPaths, a fixed-income analytics platform specializing in mortgage and option-adjusted analytics.  Beginning his tenure as a software engineer in the quantitative development group, Gene advanced through financial modeling, client service, and product management roles.  As Managing Director and Partner, he drove the firm's daily operations and shaped its product and strategic vision.  Under his leadership, the client services team supported a diverse spectrum of front- and mid-office financial professionals, working closely with traders, portfolio managers, risk managers, and asset liability managers to leverage PolyPaths for bond pricing, hedging, risk analysis, income forecasts, investment optimization, and stress testing.  Gene successfully co-led the strategic sale of PolyPaths to Numerix in 2023.  Following the acquisition, he served as Head of Client Services, spearheading Numerix’s global pre-sales and sales initiatives and directing the end-to-end customer experience in fixed income.

Gene holds a B.A. in Cognitive Science from UC Berkeley, an M.S. in Computer Science from the University of Chicago, and an MBA from Columbia Business School. He is a CFA charterholder.

David Oh has nearly a decade of experience in financial modeling and technology solutions, specializing in client services and product development. After earning his degree in International Studies and Physics from Johns Hopkins University, he joined PolyPaths as a liaison between clients and quantitative developers.

Since Numerix’s acquisition of PolyPaths, David has continued to support clients, shape product enhancements, and drive integration into the Numerix technology stack. He works closely with clients to optimize system usage, scopes new features to meet evolving needs, and serves as an SME for sales and marketing initiatives. His expertise ensures that financial institutions benefit from innovative, client-driven solutions in risk management, pricing, and analytics.

Aaron brings substantial hands-on experience and an enthusiasm for quantitative finance to his role heading the client services team for the PolyPaths product at Numerix. With over 14 years of delivering and implementing software solutions to clients across the fixed-income sector, Aaron's unique expertise positions him as a key product expert, working closely with risk managers, traders, information technology, and model validators to implement unparalleled, production-quality analytics. Aaron holds a B.S. in Mathematics from Carnegie Mellon University.