If you're a U.S. citizen, if you're in the United States, you live in the most dynamic economy in the world, the best possible place to be an investor. And if you're investing in the S&P 500 or the total stock market index, by definition those largest companies are international businesses.

So you have international exposure, but you have it at the least possible cost and you have it in the country that has the best regulations around investments. So your investments are as clear as they can be, whereas in some international markets they're a little more opaque. So for that reason, I don't see the need to be in international funds.