AbstractIn this article, we examine whether and how small investors’ social media activity is associated with subsequent bond credit spreads. We use extensive data from posts/comments on social media 30 days before the bond issuance announcement date to identify their implied power and find that the more posts/comments, the smaller the bond issuance spreads. We further find that information quality improvement of posts increases this negative relation between social media activity and bond cost, and that posts directly related to issuers’ fundamentals and/or debt financing drive our main results. Additional tests show that the effect is more salient when there is a greater demand for information quality or when macroeconomic conditions worsen.