And remember, stock markets are volatile and stock prices go up and down often (more on that later), so you can’t worry every time your stocks take a little dip. According to Ron Lieber, author and “Your Money” columnist for The New York Times, “stocks are most useful for long-term goals. So unless those goals have changed in the last few days, it probably doesn’t make much sense to overhaul an investment strategy based on a blip of market activity.”