Our paper examines whether investor opinions expressed in social media predicted stock returns of financial firms during the 2007–2009 global financial crisis. We conduct a textual analysis of the articles published on the stock market insight website Seeking Alpha before the crisis and find that banks that were described in articles with a higher fraction of negative words experienced (1) sharper drops in stock prices, (2) larger increases in expected default probability, and (3) greater surges in nonperforming loans during the crisis. Our evidence suggests that wisdom of crowds provides valuable information on how banks weather a forthcoming crisis.

We find that changes in short interest predict banks’ stock returns during two recent banking crises. Furthermore, before the 2007–2008 crisis, short interest increased more for banks with worse performance during the Long-Term Capital Management crisis of 1998. We also find that changes in short interest predicted banks’ loan quality and default risk during the 2007–2008 crisis. The results are stronger for banks with higher levels of risk-taking. Overall, our findings indicate that short sellers were informed about the persistent risky business models of banks and shorted those banks before the 2007–2008 crisis.