Yajing (Stella) Wang

Yajing (Stella) Wang

School of Accounting and Finance
The Hong Kong Polytechnic University
Ph.D. Candidate in Finance
yajing-stella.wang@connect.polyu.hk

I am a fourth-year Ph.D. Candidate in Finance at the School of Accounting and Finance, The Hong Kong Polytechnic University.

My research interests include corporate finance, focusing on innovation and climate finance, as well as asset pricing, with an emphasis on derivatives and cryptocurrency.

Research Interests

Corporate Finance: Innovation, Climate Finance

Asset Pricing: Derivatives, Cryptocurrency

Download CV SSRN

Education

Ph.D. in Finance

The Hong Kong Polytechnic University, September 2022 - present

Supervisor: Jie CAO, Professor, Hong Kong Polytechnic University School of Accounting & Finance

Co-Supervisor: Xintong ZHAN, Li-Dasan Chair Professor, Fudan University School of Management

M.S. in Finance

University of International Business and Economics, September 2017 - June 2020

Supervisor: Weixing WU, President, Capital University of Economics and Business

Co-Supervisor: Zhuo HUANG, Deputy Dean, Peking University National School of Development

BEc in Finance

Shandong University, September 2013 - July 2017

Working Papers

Opioid Crisis and Firm Downside Risks: Evidence from the Option Market

with Jie Cao, Amit Goyal, Xintong Zhan, and Weiming Zhang
Abstract: We explore how the opioid crisis exposure affects firm downside risks implied from equity options. Using a large sample of public firms from 1999 to 2020, we find that firms headquartered in or having establishments in regions with higher opioid death rates have higher costs of protection against downside risks. Employing various robust difference-in-differences settings, we show that the effects are reversed following exogenous anti-opioid legislation, supporting a causal interpretation. Further analysis shows that the opioid crisis heightens firm risk by lowering labor productivity. We document greater impacts among firms with higher reliance on labor and limited local labor supply.
AFA (2025) poster, Finance Down Under (2025)

The Salience of Climate Change and Green Patents Review: Evidence from Climatic Disasters

with Jie Cao, Tao Shu, Xuan Tian, and Xintong Zhan
Abstract: This paper investigates the causal effect of patent examiners’ climate change beliefs on their green patent review behavior and green innovation outcomes. Using granular data on U.S. patent examiners across geographic locations from 2012–2020, we leverage climatic natural disasters as plausibly exogenous shocks to examiners’ climate change beliefs. We find that examiners grant significantly more green patents following local climatic disasters, with these patents showing significantly higher quality. Further analysis suggests that the effect stems from increased effort by disaster-exposed examiners during green patent reviews. These higher-quality green patents subsequently lead to greater reductions in corporate carbon emissions. We find no comparable effects for either non-green patents or non-climatic natural disasters, highlighting that examiners’ climate change beliefs exclusively influence green innovation outcomes.
AEA (2025) poster, Best Paper in ESG and Sustainability (AFBC 2024)

Bitcoin Option and Stock Return Predictability

with Jie Cao, Gang Li, and Xintong Zhan
Abstract: This paper studies the interconnections between cryptocurrency and traditional financial markets. We find a novel and surprising predictive relationship between the Bitcoin options market and stock market returns in time series. The implied volatility smirk measure (VSBTC), defined as the difference in the implied volatilities of out-of-the-money and at-the-money Bitcoin options, serves as a strong and robust predictor of future U.S. stock market excess returns from days to weeks. The cross-market return predictability also applies to international stock markets and the U.S. corporate bond markets. We further explore and suggest some economic mechanisms that drive such a relationship.

Teaching Experience

Tutorial Instructor

School of Accounting and Finance, The Hong Kong Polytechnic University

AF3313 (Undergraduate): Business Finance, Fall 2023

AF4513 (Undergraduate): Corporate Social Responsibility, Fall 2024

Teaching Assistant

School of Accounting and Finance, The Hong Kong Polytechnic University

AF5373 (Master): ESG Investment and Green Finance, Spring 2023

AF6305 (Ph.D.): Asset Pricing and Investment Research, Fall 2023, Fall 2024

AF6306 (Ph.D.): Contemporary Issues in Empirical Finance, Fall 2024

Presentation

Selected presentations (*by coauthor)

  • The 2024 Journal of Contemporary Accounting and Economics Annual Symposium (PhD Session), 2024, Hong Kong, China.
  • The 2024 "Climate Finance and E. S. and G: Shaping a Sustainable Future" Conference (Poster Session), 2024, New York, U.S.
  • The 2024 Indonesian Financial Management Association (IFMA) International Conference, 2024, Bali, Indonesia.
  • Research in Behavioral Finance Conference (RBFC), 2024, Amsterdam, Netherlands.
  • The University of Sydney Business Financing and Banking Annual Workshop, 2024, Sydney, Australia.
  • The 37th Australasian Finance and Banking Conference (AFBC), 2024, Sydney, Australia.
  • Chinese University of Hong Kong, 2024, Hong Kong, China.
  • The 2025 AEA PhD Student Poster Session, 2025, San Francisco, U.S.
  • The 2025 AFA PhD Student Poster Session, 2025, San Francisco, U.S.
  • Finance Down Under Conference*, 2025, Melbourne, Australia
  • Deakin University*, 2025, Melbourne, Australia
  • Australian National University*, 2025, Canberra, Australia
  • Chinese University of Hong Kong-Shenzhen, 2025, Shenzhen, China
  • Seoul National University*, 2025, Seoul, South Korea
  • Korea University*, 2025, Seoul, South Korea
  • Sungkyunkwan University*, 2025, Seoul, South Korea