How can I find out the reasons behind changes in a company's stock price? I'm doing an assignment in which I need to find two points of significant points of change on a company's stock chart and explain why. So far, all the articles I've seen only state that the stock price has fallen/ risen and that certain people have bought/ sold the stock and experts say to buy/ sell. However, I need to know the actual reasons behind the rise/ fall (ex: technological development, article written influencing people against company, etc). I also need to categorize the reason as a beta or non-beta risk.