Digital financial services have lowered barriers to investment and increased Generation Z participation in app-based financial markets, but easier access is not always accompanied by disciplined financial behavior and adequate risk evaluation. This study examines the effects of financial behavior, risk perception, and financial technology (FinTech) usage on Generation Z investment decisions. A quantitative explanatory design with a cross-sectional survey was applied to 200 valid respondents who had used FinTech services and participated in digital investment activities. Data were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The results show that financial behavior has the strongest positive and significant effect on investment decisions (beta = 0.392, p < 0.001). Risk perception also has a positive and significant effect (beta = 0.218, p = 0.001), indicating that awareness of potential loss, market volatility, platform security, and risk-profile fit supports more rational decisions. FinTech usage positively and significantly affects investment decisions (beta = 0.314, p < 0.001) by expanding access to information, transactions, and portfolio monitoring. The adjusted R-square of 0.609 indicates that the three predictors explain 60.9% of the variance in investment decisions. These findings position technology as an enabler, while financial discipline and risk awareness remain central to responsible and sustainable digital investment decisions among Generation Z.