The way people interact with the financial markets has changed dramatically as a result of the explosive rise of online investment platforms. The complicated interplay between human psychology and investment decision-making is revealed by this technical advancement. In order to provide light on the influence of behavioural biases on investor decision-making processes, this study examines the existence and significance of behavioural biases in the context of online investment platforms. This paper identifies and examines the behavioural biases frequently noticed in online investment contexts by drawing on a thorough examination of the available literature. These deeply ingrained cognitive biases frequently cause investors to make poor choices, which have an impact on the success of their portfolios and their financial situation. We go into the specific ways in which prejudices materialise within the digital investment ecosystem by exploring real-world case studies and empirical data. This article also examines the techniques used by online investment platforms to lessen the impact of biases. It looks into how robo-advisors, artificial intelligence, and algorithms might help investors understand their inclinations. The report also emphasises the need of cognitive empowerment and investor education as tools to combat these biases.