One thing I always find interesting on days like this is that, although there is much celebration about how strong the action is, nobody seems to be talking about the buys they are making.
Someone is obviously buying, otherwise we wouldn't be up 1%. But most of the articles I read indicate that traders are reticent to do much. There are always momentum players willing to chase giant moves on big volume, but it always surprises me how little buying I hear about on a day when the market is looking downright euphoric.
I suspect that it is the algorithmic and computerized traders that are primarily responsible for gunning the action rather than individual traders, and that is why the emotions don't correlate with the action. The computer-based traders have no sense of overbought or oversold -- they'll just continue to do whatever is working, and that tends to make upside momentum a self-perpetuating force.
What happened today was that a number of bears were looking for INTC's earnings report to trigger a top. What they didn't figure was that the market doesn't care about earnings right now. It's all about QE 2 and the weak dollar, and as long as the dollar remains under pressure it is going to hold this market up. Earnings are just a momentary distraction from the Fed, which is all that matters at the moment.