Rev. Shark says it so nicely I will just quote him directly

The market is perking up nicely. Breadth is improving and the Nasdaq 100 Unit Trust has a particularly bullish-looking pattern intraday. I suspect there may be some buying interest there due to the rebalancing that I mentioned earlier.

I'm not sure what impact that will have, but the fact that Google is likely to be added is intriguing. Google looks like it would be about the third-largest weighting in the index and may help generate some additional volatility.

A couple of readers asked me about the old adage I mentioned earlier, "Don't short a dull market." When market action is slow and not much is going on, there can be some surprising bursts of strength, as traders make buys out of boredom and then others jump in as they notice the action.

Market participants lean much more to the long side, so when things are slow and they are looking for something to do they are more likely to buy than sell. That at makes it dangerous to put on shorts. We are seeing a fairly good example of that right now.