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 optical and electronic components builder Fabrinet (NYSE: FN) got trashed this morning, falling as much as 14.8% on very heavy trading volume.

So what: After Friday's closing bell, Fabrinet's largest customer, Oclaro (Nasdaq: OCLR), delivered notice to end a long-lived supply relationship with Fabrinet. You might have expected competitors such as Oplink (Nasdaq: OPLK) and Ciena (Nasdaq: CIEN) to jump on the news that Oclaro was shopping around for new suppliers, but that didn't happen. The entire optical industry is in the dumps today. Hmm.

Now what: Analysts and industry watchers generally see the announcement as a negotiating ploy by Oclaro rather than a break-up letter. "[We] do not anticipate any change in Fabrinet's revenue or earnings through fiscal year 2012 based on Oclaro's announcement," explains Deutsche Bank.

So this drop feels more like a buy-in opportunity than a panic signal. Just remember to keep your options open. For example, optical networking specialist and five-star CAPS stock Infinera (Nasdaq: INFN) is also falling hard today.

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

Fool contributor Anders Bylund holds no position in any of the companies discussed here. The Motley Fool owns shares of Infinera. Motley Fool newsletter services have recommended buying shares of Infinera. 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 Motley Fool is investors writing for investors.