How can I understand how far a stock is likely to move?                                                                                                                                              The statistical distribution of prices :: Normal distribution & Log-normal distribution Normal Distribution gives equal chance of prices occurring either above or below the Mean (which is shown here as 0). We are going to use normal distribution for simplicity’s sake. If a price distribution is considered Normal , 68.20% of the time, you will be within 1 standard deviation. ...