Does Interaction on Social Media Increase or Moderate Extremeness?

Using comment streams on Seeking Alpha articles, we examine whether interacting on social media increases or moderates the extremeness of investors’ opinions. Unlike some findings from political science that show social media increases extremeness of opinions, we find that interaction on Seeking Alpha moderates extremeness. Comments become less extreme over the sequence of comments for a given article, as well as within individual comment sub-threads, and over a single user’s comments for a given article. Extremeness reduction is stronger when the article itself is more moderate, and when more users are self-identified (i.e., not anonymous). Results also suggest that the extremeness reduction triggered by Seeking Alpha interaction has capital market implications. Differences of opinion captured by stock-based measures, abnormal volume and turnover, decrease significantly after the release of Seeking Alpha articles with comments. Our results provide the first evidence of the effect of social media interaction on the updating of individuals’ opinions