The emergence of financial technology has significantly transformed investment practices, particularly through the introduction of micro-investment applications that enable individuals to invest small amounts with ease and convenience. This study examines the adoption of micro-investment applications and its influence on early investment behaviour among young investors in Chennai. The research focuses on key determinants such as ease of investment access, financial knowledge enhancement, perceived risk reduction, and digital trust, with investment confidence acting as a mediating variable. A quantitative research design was adopted, and primary data was collected from 300 respondents using a structured questionnaire. Statistical analysis was conducted using SPSS, including descriptive statistics, reliability analysis, correlation, regression, ANOVA, and Chi-square tests. The findings reveal that all independent variables significantly influence investment confidence, with financial knowledge enhancement emerging as the strongest predictor. Investment confidence, in turn, has a significant positive impact on early investment behaviour. The study confirms a full mediation model, indicating that the relationship between micro-investment application adoption factors and early investment behaviour is fully mediated by investment confidence. The results highlight that while micro-investment applications improve accessibility and reduce financial barriers, it is the development of confidence that drives consistent investment behavior among young investors. The study contributes to the existing literature by integrating FinTech adoption with behavioral finance perspectives and provides practical insights for financial institutions, application developers, and policymakers to promote informed and confident investment practices among young users