Remember when people used to go ga-ga over the fact that there are more mutual funds than stocks? You are probably too young--seriously. I'm wondering if we are heading toward a similar state with exchange-traded funds. More than 300 proposed new ETFs have been registered with the SEC. You have to figure that most will be approved. What we are seeing is an amazing amount of innovation, though not all of these ideas will find a market. Of course, many of these ETFs are sector plays; healthcare is a hot trend right now. Another group by XShares are state-specific, for those who want to invest in a particular state. Obviously, the goal here is capture pension business--that is only smart. ProShares is launching 66 new Ultra, Short and UltraShort versions of many indexes. Short seeks to invert an index. UltraShort aims to double the gains of an inverted index.

For more:
- here's an Investor's Business Daily article