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 Finisar (Nasdaq: FNSR) rallied close to 17% before closing up 14.5%, riding on the coattails of Cisco's (Nasdaq: CSCO) strong earnings report.

So what: Several optical-networking stocks rose. JDS Uniphase (Nasdaq: JDSU) and Ciena (Nasdaq: CIEN) each soared about as much as Finisar, presumably on the idea that a resurgent Cisco is reflective of industrywide demand for fast data delivery gear.

Now what: Finisar could benefit more than most as a supplier for Cisco's own branded optical-networking equipment. There’s no guarantee, of course; but I get the reasoning behind the rally. Do you agree? Disagree? Weigh in using the comments box below.

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

Fool contributorTim Beyers is a member of theMotley Fool Rule Breakers stock-picking team. He didn't own shares in any of the companies mentioned in this article at the time of publication. Check out Tim'sportfolio holdings andFoolish writings, or connect with him on Google+ or Twitter, where he goes by @milehighfool. You can also get his insightsdelivered directly to your RSS reader.

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