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 SunPower (Nasdaq: SPWR) jumped 17% today after the company was upgraded by an analyst.

So what: Citigroup analyst Timothy Arcuri said he thinks the industry is near a bottom and upgraded SunPower to buy from a hold rating. He also upgraded shares of Yingli Green Energy (NYSE: YGE) and has a buy rating on shares of Trina Solar (NYSE: TSL).

Now what: Solar stocks have been crushed in recent weeks, and analysts and investors are starting to see some value in the industry right now. We'll get a better look at how SunPower in particular is going when it reports earnings on Thursday, so I'm a little worried we're putting the cart before the horse here. If SunPower can improve margins over the fourth quarter it will be a great buy, but today's pop could be negated if results are disappointing. Short-term, I see buying this move as risky, although SunPower is my top solar stock long-term.

Interested in more info on SunPower? Add it to your watchlist by clicking here.