Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of MEMC Electronic Materials (NYSE: WFR), which makes solar-panel and semiconductor wafers, jumped 12.1% on heavy volume this morning.

So what: The company actually missed analyst expectations but more than made up for that with a tremendously optimistic outlook on 2011. The report not only game MEMC a rocket boost, but also gave a push to solar-panel rivals from Trina Solar (NYSE: TSL) to SunPower (Nasdaq: SPWRA).

Now what: MEMC's projections could be right or they could be wrong, but management would have to make a lot of faulty assumptions in order for 2011 to be anything but a good year in the solar-power industry. However, MEMC's stock looks expensive in relation to its habitually weak earnings and the best play on the sector probably lies elsewhere. Valuation matters, even in a hot sector.

Interested in more info on MEMC Electronic Materials? Add it to your watchlist.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool is investors writing for investors.