This study tests the impact of usage of Twitter as a microblogging service provider on shareholders returns and abnormal returns. In accordance with this purpose, two portfolios were created based on measurement of whether firms had a Twitter account and, if so, their number of followers and tweets and the increase in the number of followers. The returns from these portfolios indicate that better Twitter performance according to these metrics does not provide any significant increases in the abnormal returns of shareholders. Nevertheless, the market betas of greater than 1 observed in the related portfolios have revealed that these portfolios are more risky than alternative portfolios. (C) 2019 AEDEM. Published by Elsevier Espana, S.L.U.