Investors' decisions are influenced by cognitive biases like overconfidence and illusion of control. A study in Bandung, West Java, surveyed 100 individual investors to see how age, gender, and education affect these biases. The results show that illusion of control bias impacts decision-making, with gender and education moderating its influence. Overconfidence bias also affects decisions, with gender playing a role in moderating its impact. It's important for investors to be aware of these biases to make rational investment choices.