News Credibility and Influence within the Financial Markets

How does information credibility, a subjective judgment of investors, affect empirical asset pricing in financial markets? Traditional economic theories are inadequate for interpreting market responses driven by people’s subjective thinking, as these cognitive processes are not encompassed by the concept of utility. We explore these effects by using computational linguistics and deep structured learning algorithms to analyze financial newspapers and social media posts. After controlling for factors related to content and market momentum in our narrative based credibility indicator, we find that news credibility is positively correlated with the returns on assets preferred by experts and negatively correlated with assets preferred by gamblers. Based on this finding, we point out that the efficient-market hypothesis (EMH) is not appropriate in the dominant market of gamblers in the short-term. In the long-term, however, investment motivation does not significantly affect the validity of the hypothesis.