Does information uncertainty moderate the impact of investors' emotion on stock prices?

Prior studies point out information uncertainty (IU) of a stock comes from investors' overconfidence. However, overconfidence is hard to be measured. After our collections and reviews of prior studies regarding IU, we propose stock returns are affected by investors' sentiment, and this relation is moderated by IU. We use SentimentAnalyzer system, a text mining technology, to analyze the posts in a stock forum on The Motley Fool financial website to investigate the psychology of investors, and verify our hypotheses by structural equation modeling (SEM) in weekly, monthly and quarterly intervals. Our findings demonstrate that investors' sentiment positively affects the stock returns only in short-term (weekly) interval, and this relation is also affected by IU in short time. Therefore, we proposed two suggestions. In buyer side, the investors who prefer high risks and returns can choose stocks with high IU (small company size or higher volatility in prices and volumes) and good reviews in forums as their targets in next week, and avoid the stocks with bad reviews. In contrast, in seller side, investors can choose the stocks with bad reviews as their next-week targets, too.