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 thin-film-panel manufacturer First Solar (Nasdaq: FSLR) fell 10.5% today after being downgraded by an analyst.

So what: Avian Securities analyst Mark Bachman downgraded the stock on concerns over product reliability. He pointed to potentially loose core plates on the backs of modules made between October 2008 and June 2009 as his major concern. The company hasn't released any new information about manufacturing problems today.

Now what: First Solar has been replacing modules made between June 2008 and June 2009 for over six months and we've known about manufacturing issues since February. It's unclear if the problems Bachman is pointing to are new and he acknowledges that some of the panels with problems may have already been replaced.

This really looks like a non-story given the company's previous disclosure and writedowns related to manufacturing problems in the time frame Bachman points to. Whether you're bullish or bearish on First Solar, I don't see this as a reason to change your investment thesis today.

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