This study aims to achieve two main objectives: first, to examine the impact of fundamental, technical, and bandarmology information, along with social media influencers, on overconfident investors; second, to investigate the role of social media influencers in moderating these influences. Data was collected via questionnaires distributed through Google Forms, using multistage purposive random sampling, with 981 Indonesian investors participating. The data analysis was conducted using structural equation modeling (SEM) with smartPLS software. Findings indicate that social media influencers significantly mediate the impact of fundamental, technical, and bandarmology information on overconfident investor behavior. Among these, bandarmology information provided by social media influencers is the most influential, contributing to investor overconfidence. The study also reveals partial mediation by social media influencers on the influence of these information sources on overconfidence in the Indonesian Stock Exchange.