The Motley Fool has a great brief on Mutual Funds versus Exchange Traded Funds (ETFs). ETFs have become so popular in the last couple of years, it is a rather amazing phenomenon. In fact, there are now mutual funds that invest in ETFs that track indices based on predictions predicated upon research and analysis of where the market is going. Mutual funds are still the best investment for your 401(k), or any doller cost averaging program right now. However, it will be interesting to see how the Sharebuilder brokerage model will work. I think we may see something like this within a company’s 401(k), seeing how popular the low fee index ETFs have become.