Kurt Brouwer submits: Exchange traded funds (ETFs) have many of the built-in advantages that mutual funds have, but there are also differences. In my view, the biggest difference is not the fact that ETFs trade throughout the day or even how ETF pricing works, but rather that ETFs have a very short operating history. We use both mutual funds and ETFs so I am not at all negative about exchange traded funds, but I am aware that there will be growing pains as the ETF industry matures. Compl