Q: Who sets stock prices?

- J.N., Seattle

A: A company's stock price isn't set by anyone. Rather, once shares have been sold by the company to the public (either via an initial public offering or a secondary offering), they trade fairly freely in the stock market.

It's not unlike trading cards, which are valued at what people will pay for them. If demand rises or falls, so do prices. That's why, if there's bad news about a company, its stock usually will soon be worth less - and vice versa.