The research paper examines how behavioural biases of anchoring, availability heuristic and overconfidence affect the investment decisions of the retail employees in the National Capital Region (NCR) of India in the private sector. Filling an important gap in empirical research on this population group, the study follows a quantitative, cross-sectional survey design and stratified random sample to gather information on 312 full-time employees. Each bias was measured with validated multi-item scales and the reliability and validity of these constructs were established using exploratory factor analysis as well as confirmatory factor analysis. Results of multiple linear regression analysis showed that the three behavioural biases have positive and significant impacts on investment decision-making with overconfidence having the highest impact (0.29, p < .001). The results also revealed that emotional cues like stress at the workplace and competition among peers enhance the impacts of these biases and the probability of poor and risk-prone investment decisions. The findings support the need of special investor education programmes and organisational interventions that consider cognitive and emotional aspects of financial decision-making. This information forms good knowledge to the researchers, practitioners, and policymakers who aim at improving financial well-being of the increasing number of NCRs in the private sector.