Behavioral Finance Overview

Principles

Definition

Behavioral finance is an academic field that integrates insights from psychology and economics to understand how cognitive biases, heuristics, and emotions influence the financial decisions of individuals and institutions, often leading to deviations from the predictions of traditional rational choice models. It investigates market anomalies and investor behavior by examining the psychological factors underlying judgment and decision-making in financial contexts.

Ontological type

Cognitive Biases

Key Theories

Market Anomalies

Key developments

Key Figures

Behavioral Foundations era

Andrei Shleifer [1], affiliated with Harvard University [3] and the Massachusetts Institute of Technology [4] in this era, helped shape the behavioral foundations of asset pricing. His key contributions include developing investor sentiment concepts and models, as seen in A model of investor sentiment [7] (1998), Positive Feedback Investment Strategies and Destabilizing Rational Speculation [8] (1990), and Investor Sentiment and the Closed-End Fund Puzzle [9] (1991), which clarified how biases and bounded rationality can generate mispricing and influence return dynamics. David Hirshleifer [2], linked with Stanford University [5] and the University of Washington [6] during this period, helped build the behavioral-pricing literature by emphasizing the psychology of overreaction and mispricing. His notable contribution in this era is the 1998 paper Investor Psychology and Security Market Under‐ and Overreactions [10], which formalizes how investor psychology drives systematic under- and overreactions and helps explain the return patterns highlighted by the Behavioral Foundations era.

Attention and Microstructure era

Terrance Odean [1] is a leading behavioral finance scholar associated with University of California, Berkeley [3] and University of California, Davis [4] during this era. His work illuminated how attention and news affect buying behavior and how individual investors' trading can erode wealth, as shown in All That Glitters [5], Trading Is Hazardous to Your Wealth [6], and Just How Much Do Individual Investors Lose by Trading? [7], underscoring the importance of attention-driven channels for pricing and liquidity. Brad M. Barber [2] is a prominent figure in this era, connected with University of California, Berkeley [3] and University of California, Davis [4]. His collaborative work on the same trio of papers demonstrates how attention and trading costs contribute to the persistent underperformance of individual investors, illustrating the limitations of rational trading and the impact on market microstructure, as reflected in All That Glitters [5], Trading Is Hazardous to Your Wealth [6], and Just How Much Do Individual Investors Lose by Trading? [7].

Sentiment-Driven Retail Finance era

Peter C.B. Phillips [1] is a leading econometrician whose scholarly affiliations include the University of Washington [3] and Yale University [4] during the Sentiment-Driven Retail Finance era. In 2011, his paper EXPLOSIVE BEHAVIOR IN THE 1990s NASDAQ: WHEN DID EXUBERANCE ESCALATE ASSET VALUES?* [7] advances understanding of how exuberance can inflate asset values, illustrating the salience of sentiment in price formation. Joseph Engelberg [2] is a prominent scholar whose institutional associations include the University of California, San Diego [5] and the University of Colorado Boulder [6]. His 2011 work The Causal Impact of Media in Financial Markets [8] demonstrates a causal role for media in shaping asset prices and liquidity, a foundational insight for analyzing platform-driven attention in this era.