In this video, we walk through the process of calculating the standard deviation of returns for individual stocks using historical data (x-post returns). We cover the key formula, the steps to find the mean, variance, and how to apply the correct adjustments. This is a crucial concept for exams, so we break down the calculations in a simple and clear way. You'll also learn about the distinction between x-post and x-ante returns and how to handle these in real-world scenarios.