@NathanG - You don’t have to figure out the beta index yourself – although I think there are some formulas that will let you do that.
Instead, it should be listed in the prospectus for your portfolio. If you’re like me, it’s probably one of the many numbers you overlook because you don’t know what it means.
In some portfolios they may not use the word “beta” but may instead use the word “risk,” which is easier to understand.
I think risk is important for another reason though, kind of opposite to what the article concludes. You may decide that a low beta portfolio is actually better for you, in the long term. It will be less profitable, yes, but it will be less risky too, producing safer returns. It depends on your investment temperament and horizons I would suppose.