As you diversify you need to evaluate your investments — and your potential investments — on their own merits, as well as what they bring to your overall portfolio.
It's not enough that an investment is in the right asset class or subclass — you'll need to make sure that the investment you choose has the best chance of helping you meet your financial goals. This means doing your research before you invest, as well as reviewing your portfolio from time to time to make sure that all of your investments are meeting your performance expectations.
Don Kittell