This study examines whether investors’ engagement with social media commentary influences their reliance on information when making investment decisions. Social media platforms provide a low-cost, interactive environment for disseminating financial information. However, they also introduce wide variation in the quality of content, requiring users to evaluate the value relevance of peer commentary. Drawing on dual processing theory, I argue that actively engaging with social media commentary, such as commenting or reacting, encourages deliberative System 2 thinking, enabling investors to better discriminate between content and rely more heavily on information with greater value relevance. Across three experiments, I manipulate the level of user engagement as well as the valence and value relevance of social media comments. In the first experiment, I find that, compared to passive observers, investors who engage by responding with a thoughtful comment are less influenced by low-value-relevance comments. In the second experiment, I show that thoughtful engagement heightens sensitivity to the value relevance of the social media comment. Specifically, investors who respond with a thoughtful comment rely more on more value-relevant comments and rely less on less value-relevant ones. Finally, in my third experiment, I show that merely reacting to a social media comment, for example with an up or down-vote, reduces the influence of less value-relevant information. I also find that users who actively engage, by providing a thoughtful comment or a reaction, are more confident in their judgments when they encounter inconsistent information. Together, the findings indicate that active engagement mitigates investors’ overreliance on low-value commentary, thereby improving investment decisions. These results have implications for investors who use social media, regulators concerned with investor protection, and researchers studying how peer discussions shape financial decision-making and market outcomes.