I do not know why we can see increased trading in the industrials and financial sectors. It could be because the investors are waiting to see Chrysler bankruptcy and how it will affect automotive market, or those investors who bought in February decided to pocket a profit or it could be something else. I know one thing - such big volume means that big number of investors (or small number of investors with big money) started to relocate their investments and that may lead to the change in the supply/demand balance and as a result to a change in the stock market sentiment.
I would personally watched very closely stock market over the next couple of sessions to see how the market will react on this volume. I am not telling that the market will drop tomorrow, it could continue to move up, however I would prefer to stay in cash for now. Maybe I'm wrong and maybe I'm loosing opportunity to make some profit, yet, I consider there are moments when it could be useful to stop and monitor for a while in order to see the development of events - in current situation development of reaction on this high volume.