Team Members

Deane Yang, PhD - Director of Research

Dr. Deane Yang is the Head of Research at Andrew Kalotay Associates. In this capacity, he is responsible for the research and development of interest rate models and valuation models for fixed income securities and interest rate derivatives. In addition, he oversees the valuation and analysis for AKA's advisory clients.

Deane led the development of the valuation libraries TIPSVal™ for inflation-indexed bonds, FloatVal™ for floating rate and structured notes, and CurvePlus™ for yield curve analytics. In the past Deane has developed the SwapSpread™ asset swaps calculator, SwapVal™ interest rate derivatives valuation library, and AgencyBondPricer™, a desktop application for pricing agency debentures. He is also the co-inventor, in collaboration with Andy Kalotay, the CLEAN™ mortgage-backed security valuation library, and Volatility Reduction Measure for FAS 133 hedge effectiveness testing.

Along with Andy, he was an advisor to the Bond Market Association (BMA, now SIFMA) task force on the new quotation formula for large agency European-type callable securities (ECS). Deane authored the BMA guidelines for implementation of the new convention and provided a spreadsheet-based BMA ECS calculator for practitioners.

Deane has previously worked at Sumitomo Bank Capital Markets, where he worked on credit risk, VaR, and interest rate derivative pricing models.

A Professor of Mathematics at Polytechnic Institute of New York University, he has held faculty positions at the Courant Institute of Mathematical Sciences at New York University, Columbia University, and Rice University. His academic research areas include convex geometry, geometric and analytic inequalities, and Riemannian geometry. Deane received a BA in Mathematics and Physics from the University of Pennsylvania and a PhD in Mathematics from Harvard University.

Leslie Abreo, Director of Product Development

Leslie Abreo directs new product development and manages client support at Andrew Kalotay Associates, as well as overseeing the company’s finance and operations functions.

He recently directed the development of iteRate™, a program that extracts implied optionless yield curves from callable tax-exempt curves. He has co-authored papers on various topics of debt management with Andy Kalotay including bond insurance, debt refunding, tax-driven transactions, and hedge effectiveness testing.

Leslie holds a BBA in Finance, summa cum laude, from Baruch College and an MS in Financial Engineering from Polytechnic University. He has completed several advanced level graduate courses at the Courant Institute of Mathematical Sciences at New York University.

View Leslie Abreo's profile on LinkedIn

Radek Wyrwas, CFA Senior Fixed Income Analyst

Radek Wyrwas is a senior fixed income analyst at Andrew Kalotay Associates responsible for debt pricing, valuation software testing, and debt management analyses for agency, corporate, and municipal issuers. Since joining AKA in 2012, Radek has worked on a number of projects which include:

• Historical valuation of outstanding agency-backed mortgage pools to facilitate construction and back-testing of indexes

• Daily pricing of agency debt

• Quarterly valuation of utility client debt

Radek holds a BA in Economics from Baruch College in New York and passed all three levels of the CFA Program.