The efficient-market hypothesis (EMH) is one of the most important economic and financial hypotheses that have been tested over the past century. Due to many abnormal phenomena and conflicting evidence, otherwise known as anomalies against EMH, some academics have questioned whether EMH is...

We study the relation between hedge fund equity holdings and measures of informational efficiency of stock prices derived from intraday transactions, as well as daily data. Our findings support the role of hedge funds as arbitrageurs who reduce mispricing in the market. Hedge funds invest in...

We examine the relation between changes in hedge fund stock holdings and measures of informational efficiency of equity prices derived from transactions data, and find that, on average, increased hedge fund ownership leads to significant improvements in the informational efficiency of equity...

This paper analyzes how newly introduced transparency requirements for short positions affect investors' behavior and security prices. Employing a unique data set, which contains both public positions above and confidential positions below the regulatory disclosure threshold, we offer several...

This note investigates the causes of the quality anomaly, which is one of the strongest and most scalable anomalies in equity markets. We explore two potential explanations. The "risk view", whereby investing in high quality firms is somehow riskier, so that the higher returns of a quality...

We study how sophisticated investors, when faced with shocks to information environment, change their information acquisition and trading behavior, and how these changes in turn affect market efficiency. We find that, after exogenous reductions of analyst coverage due to closures and mergers of...

This paper examines how gambling-motivated trading affects aggregate financial market outcomes. Using a unique global gambling data set covering 39 countries, we show that the dollar volume of stock market gambling is at least 3.5 times the combined volume of “traditional” gambling outlets...

Stock prices occasionally move in response to unverified rumors. I propose a cheap talk model in which a rumormonger's incentives to tell the truth depend on the interaction between her investment horizon and the information acquisition decisions of message-receiving investors. The model's key...

Using a recent stock market liberalization reform policy in China-the Stock Connect-as a quasi-natural experiment, this study examines the effect of stock market liberalization on market efficiency. Employing a dataset of 17,086 Chinese listed firms covering 2009 to 2018, we find that stock...