This is where a little research comes in handy. As with any investment, one should do plenty of research before signing the check. Information on any mutual fund is available from the parent company which manages it. In addition, one can use the internet. Most funds with consistent records over the last ten years will probably continue to do well.
Research can do much to minimize one's investment risk but can never completely negate it.
This is why some choose to keep their savings in the bank. But this just isn't the best idea. Yes, it's safe and free of risk. What it doesn't do is put your money to work in the most efficient and profitable fashion. While money that sits in a savings account does indeed earn interest, those earnings are usually rubbed out by inflation.