Social media has provided a rich opinion content that is valuable for diverse decision-making processes (Montoyo et al., 2012;Oliveira 2016), and sentiment analysis is being increasingly used to predict stock market variables (Antweiler and Frank 2014;Yu eta l., 2013;Schumaker et al., 2012).
social media messages are a useful source for supporting stock market decisions (Bollen et al., 2011;Oliveira et al., 2013).