“Low cost is the single best predictor of subsequent performance [for mutual funds] … it’s definitely not past performance.”, according to the director of fund research at Morningstar.

Do you know what the expense ratios are for the funds in which you’re invested? Or the blended expense ratio for your portfolio?

With a five-year bull market behind us, even ordinary mutual funds and ETFs are posting superficially attractive historical performance numbers.

You can read the entire May 31, 2014 New York Times “Your Money” feature here.