How do rumors spread? Research on why misinformation continues to influence reasoning has primarily focused on narrow timeframes in controlled laboratory settings. We advance the study of why rumors persist—even after valid corrections have been presented—by leveraging a unique collection of Twitter data covering four specific political events, including the Boston Marathon bombing and the death of Antonin Scalia. Combining these large datasets with machine learning techniques, we show how “corrective” information (such as the capture of suspects) affects the transmission of rumors up to 10 days after the incidents occurred. In several cases, we show that Twitter users estimated to be conservative are more likely to continue spreading rumors even after such causal explanations have been provided by public authorities. Furthermore, many of the rumors originate with a small number of conspiracy-oriented websites. We discuss cognitive mechanisms underpinning these findings such as motivated reasoning and the impact of the correction’s source credibility. The structural features that make social media an effective tool for facilitating collective actio