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 Chinese solar-wafer maker LDK Solar (NYSE: LDK) sank 10% Friday after its current-quarter and full-year outlook disappointed investors.

So what: LDK's revenue guidance cut for the second quarter was so dramatic -- it now sees $480 million to $500 million versus the previous guidance of $710 million to $760 million -- that investors are going to have a tough time banking on management's future guidance. When you couple those credibility issues with the strong industry tailwinds also being felt by peers like JA Solar (Nasdaq: JASO), today's drop seems justified.

Now what: I'd continue to keep my distance from LDK. Management also cut its full-year revenue outlook to about $2.6 billion from $3.6 billion, and with such a heavy debt load, investors are also worrying about the company's long-term viability. For investors who really want some solar exposure, the more financially sound and operationally healthy Yingli Energy (NYSE: YGE) seems like a better bet.

Interested in more info on LDK? Add it to your watchlist.

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Try any of our Foolish newsletter services free for 30 days. 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 Fool's disclosure policy always gets a perfect score.