One of my college roommates taught herself about the stock market for more than three years, but why did she say that she never bought any stocks?

There are two situations. One is that she might lie and not want to tell the questioner the truth. One is: to tell the truth, she just studies or analyzes the stock herself, and does not use money to operate it. It's like learning knowledge but it's useless. At this stage, it's just an armchair strategist, and we don't want to talk nonsense and hurt people and lose money.