| Abstract |
We ask how social media impacts the role of short sellers in financial markets. We find some evidence consistent with manipulation. Prior to high short interest, a stock's social media tone is abnormally positive, but its traditional media tone is not. Once highly shorted, social media tone flips and is abnormally negative. Using the firm-by-firm introduction and temporary suspension of short selling in China as natural experiments, we find that both the volatility of social media tone and the number of posts increase when a firm becomes shortable, and then decrease when shorting was suspended. Highly shorted firms with pump-and-dump social media patterns also have pump-and-dump stock return patterns and abnormally high trading volume. Manipulative social media tone is more likely when there are more posts from active social media users, who are perhaps better able to influence other users. Our findings are consistent with the idea that social networks and social media can enable manipulation. |