The importance of this comes into play more with the funds that try to imitate other market areas. If the fund is trying to return against a benchmark following the financial sector, you would want to see weighting mostly in finance stocks and positions. Within that, you want to make sure that it is not overly weighted into one bank or financial company, because that would be the same as putting all of your eggs into one basket. So before you invest in a fund, take a look and see what makes it up and ensure you agree with it.