Price-Based Return Comovement
Investors appear to group companies based on their stock-price levels. This can cause excess-comovement.
Research
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Research program 01
Investors appear to group companies based on their stock-price levels. This can cause excess-comovement.
Companies operating in less popular countries (among Americans) trade at a substantial discount in the US. Country popularity also affects foreign direct investment and cross-border mergers.
Investors appear to treat IPOs like lotteries. This can cause temporary IPO overpricing and poor long-run performance.
Issuing financial disclosure documents that are difficult to read can cause firms to trade at substantial discounts.
Founder CEOs of S&P 1500 firms appear more confident (overconfident?) than their non-founder counterparts. Our finding may explain why large publicly traded firms managed by founder CEOs behave so differently.
The presence of a well-functioning shorting market can help correct under-pricing.
We put forward that investors generally are less excited about portfolios than they are about individual companies and that this has important asset pricing implications.
Our paper advocates for text-based methods as a complementary tool to investor surveys for extracting investor perceptions. Our paper also provides a possible (partial) reason what causes the seeming overpricing (and low subsequent returns) of short-leg securities.
Our study documents how our increasing reliance on big data and technology is reshaping the role of human labor in finance.
We use AI-driven interviews with 1,540 investors across ten countries to reveal thirteen distinct mechanisms that people actually use to pick stocks, exposing major heterogeneity and gaps in existing asset-pricing theories.
Contrary to popular accounts, among currently childless adults who remain open to having children, economic concerns matter far more than lifestyle autonomy.
Research program 02
Social Interactions
It Pays to Have Friends
with Seoyoung Kim · 2009 · Journal of Financial Economics 93, 138-158
Social ties between corporate directors and CEOs appear to affect directors’ monitoring effectiveness.
Wisdom of Crowds: The Value of Stock Opinions Transmitted through Social Media
with Hailiang Chen, Prabuddha De and Yu (Jeffrey) Hu · 2014 · Review of Financial Studies 27, 1367-1403
Stock opinions transmitted through social media can be very valuable.
Information Sharing and Spillovers: Evidence from Financial Analysts
with Jose Liberti and Jason Sturgess · 2019 · Management Science 65, 3624-3636
High-skill finance professionals owe much of their success to the colleagues that surround them.
The Rate of Communication
with Shiyang Huang and Dong Lou · 2021 · Journal of Financial Economics 141, 533-550
We quantify how contagious financial news and opinions are.
Listening in on Investors’ Thoughts and Conversations
with Hailiang Chen · 2022 · Journal of Financial Economics 145, 426-444
The information that investors value and the information they end up sharing with other investors can be very different (and of lower quality).
The Impact of Word-of-Mouth Communication on Investors’ Decisions and Asset Prices
2023 · Handbook of Financial Decision Making
A survey of the empirical literature on the presence and economic consequences of word-of-mouth communication among investors.
Did the Game Stop for Hedge Funds?
with Jun Chen and Melvyn Teo · 2024
Retail investors increasingly use social media to coordinate for ideological or strategic considerations.
Giving Users What They Want: Social Media and Anomalies
with Joseph Engelberg, Runjing Lu and William Mullins · 2026
Social media rewards creators for producing bullish content about stocks with low expected returns, helping amplify optimistic narratives about short-leg securities.