Pengaruh Penggunaan Media Sosial, Herding Bias, dan Overconfidence terhadap Keputusan Investasi Saham: Peran Mediasi Niat Investasi pada Investor Milenial di Kalimantan Barat

The increasing activity of stock investment among millennial investors is increasingly influenced by digital information and behavioral factors. This study aims to examine the effects of social media use, herding bias, and overconfidence on stock investment decisions and to investigate the mediating role of investment intention among millennial investors in West Kalimantan. A quantitative approach was employed involving 200 millennial investors selected through purposive sampling. Data were collected using a Likert-scale questionnaire and analyzed using Structural Equation Modeling–Partial Least Squares (SEM-PLS) with SmartPLS. The findings indicate that social media use and overconfidence have positive and significant effects on stock investment decisions, whereas herding bias has no significant effect. Furthermore, social media use and overconfidence significantly influence investment intention, while herding bias does not have a significant effect. Investment intention mediates the effects of social media use and overconfidence on stock investment decisions but does not mediate the effect of herding bias. These findings suggest that millennial investors stock investment decisions are more strongly associated with exposure to digital information, confidence in their own abilities, and the formation of investment intentions than with the tendency to follow other investors decisions.