How Fear of Missing Out Connects Behavioral Biases to Stock Investment Decisions among Gen Z in Indonesia

Generation Z investors increasingly dominate the Indonesian capital market with high social media exposure raise concerns about behavioral biases in investment decision-making. This study examines the effect of herding behavior and availability bias on stock investment decisions among Generation Z investors in Indonesia, with Fear of Missing Out (FOMO) as a mediating variable based on behavioral finance theory. A quantitative cross-sectional survey of 200 Generation Z investors selected through purposive sampling was analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The findings indicate that herding behavior and availability bias positively and significantly influence stock investment decisions, and that FOMO also positively influences stock investment decisions. Furthermore, FOMO significantly mediated both relationships in a complementary pattern, with mediation proportions of 35.0% for availability bias and 16.8% for herding. These results highlight the critical role of cognitive biases and emotional factors in shaping stock investment decisions among Generation Z. The implication is that investors should set investment criteria before acting on trending stocks, trading applications could add brief risk prompts, and regulators could strengthen disclosure for finfluencer content, although their effectiveness needs testing