The Impact of Social Influences on Investment Decision-Making: A Multi-Method Analysis of Vietnamese Investors

This study explores the impact of social influences on investment decision-making, focusing on Vietnamese investors and employing a multi-method approach. Drawing on Social Contagion Theory, Behavioural Finance Theory, and Information Cascade Theory, the research examines how social media, peer pressure, and expert opinions shape investment behaviour. A representative sample of 368 individual investors was analysed using Partial Least Squares Structural Equation Modelling (PLS-SEM) and fuzzy-set Qualitative Comparative Analysis (fsQCA), revealing significant direct effects of social influences, moderated by investment self-efficacy and risk perception. Notably, novice investors were more susceptible to peer pressure and social media, while experienced investors relied heavily on expert advice. The findings extend theoretical frameworks by elucidating the mediating and moderating mechanisms of social influences and providing boundary conditions based on investor experience. Methodological contributions include the integration of quantitative and qualitative approaches and advanced analytical techniques. Practical implications highlight the need for investment platforms to provide tailored decision-support tools, financial advisors to enhance investor self-efficacy, and regulators to address misinformation risks in digital platforms. Despite limitations such as reliance on self-reported data and a cross-sectional design, the study offers a robust foundation for future research into the dynamic interaction of social and cognitive factors in financial decision-making.