Ethan Fang

About Ethan Fang

Most of quantitative finance borrows its mathematics from physics. Few practitioners follow that thread back to first principles, to understand not just what models compute, but why they work, and where they break down. That perspective has shaped how I design, validate, and own risk models in practice. I’m particularly interested in how models behave under stress and during regime transitions, where model assumptions meet market structure. By training, I’m a mathematician: Ph.D. from the University of Wisconsin–Madison, B.S. from Peking University, former member of China’s National Mathematical Olympiad training team. Over 18+ years, I’ve built and owned quantitative risk frameworks closest to the trading desk, including pre-trade PFE analytics at Citigroup, Basel IMM architecture at Morgan Stanley, senior model validation at EY, equity desk risk ownership at Wells Fargo (Executive Director), and cross-asset advisory at Jefferies, spanning rates, equity, credit, and FX derivatives. I also teach Financial Engineering at Stevens Institute of Technology, staying close to how the next generation of practitioners think about markets.I’m interested in connecting with others working at the intersection of models, market structure, and real-world constraints.

Experience

1. Senior Quantitative Risk Consultant

   Jefferies

   Feb 2025 — Present · New York, NY, US

   Led the design of a fixed income counterparty risk framework connecting model structure with market behavior, ensuring interpretability and applicability to trading decisions- Led end-to-end design of a fixed income counterparty risk PFE modeling framework as senior technical lead, coordinating across trading, market risk, technology, and external vendors. Established the economic interpretation of model outputs and the theoretical foundation connecting market dynamics to risk representation- Partner with CVA Market Risk leadership on rates counterparty exposure and credit derivative structures, including contingent CDS and credit basket hedges, translating complex quantitative model outputs into actionable hedging insights that directly inform trading desk decisions.

Education

• Peking University

  Bachelor's degree, Mathematics

• University of Wisconsin-Madison

  Doctor of Philosophy - PhD, Mathematics