Fake News in Financial Markets

Abstract

We study fake news in financial markets using a novel dataset from an undercover SEC investigation. Our setting measures both the direct and indirect effects of market manipulation. Fake articles directly induce abnormal trading activity and increase price volatility, but in addition, the awareness of fake news from the SEC investigation indirectly affects legitimate articles, causing market participants to discount all news from these platforms. These spillover consequences significantly reduce the social network’s impact on information dissemination, trading, and prices. The results are particularly acute among small firms with high retail ownership and for the most circulated articles. The equilibrium response of consumers and producers of news on these networks is consistent with models of trust, providing novel evidence on the importance of social capital for financial activity.