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 solar-power module and systems maker Yingli Green Energy (NYSE: YGE) passed behind a dark cloud today, falling as much as 10% on above-average volume.

So what: Head-to-head rival Solyndra just filed for bankruptcy protection and started laying off the majority of its staff. While solar stocks are down across the board thanks to Solyndra's disturbing and unexpected move, Yingli is taking the news harder than most: Other direct competitors such as First Solar (Nasdaq: FSLR) and SunPower (Nasdaq: SPWRB) saw only modest single-digit drops.

Now what: Analyst firm Collins Stewart responded to the drop by reiterating a buy rating with a $7.50 price target, some 40% above the current $5 level. And why not? Solyndra's very American troubles have little to do with the solar market in China, where Yingli makes most of its hay. This stock was already cheap and exploring new 52-week lows but is well-positioned with a strong balance sheet. Solar power's time will come, and Yingli is a likely winner when it happens.