The article explores how different psychological biases can affect the investment decisions of individual investors in Bangladesh. By analyzing survey responses from 196 investors in the Dhaka Stock Exchange, the researchers found that biases like cognitive dissonance, regret aversion, loss aversion, and illusion of control significantly impact investors' decision-making. These biases make investors act irrationally and can prevent them from making sound investment choices. The study shows that these psychological biases are prevalent among investors in Bangladesh, influencing their behavior in the capital market.