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-panel components maker STR Holdings (Nasdaq: STRI) fell behind a dark cloud today, dropping as far as 24.9% on very heavy volume.

So what: Management warned us a month ago that the second quarter wouldn't look too bright and the stock took a 19% beating on that news. Now the results are in, and almost exactly as good or bad as we were told to expect -- and there goes another run down the gauntlet.

Now what: STR shares have now lost some 39% of their value over a six-week period and trade for just over 8 times trailing earnings. To be fair, that's downright expensive in the solar industry as sector neighbors LDK Solar (NYSE: LDK), ReneSola (NYSE: SOL), and JA Solar (Nasdaq: JASO) all trade for less than 3 times earnings -- though all of those companies are Chinese and STR is as American as apple pie and baseball. I think it's fair to say that STR investors are getting swept along with today's general market panic, creating a great buy-in point for opportunistic investors.

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