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 communications networker Ciena (Nasdaq: CIEN) jumped as much as 10.1% on big, big trading volume before settling back at a smaller 2.5% gain.

So what: This jump is a bit of a shocker, because last night's fourth-quarter report wasn't exactly the stuff dreams are made of. Sales grew 9% year over year to $456 million, just ahead of analyst targets, but $0.03 of adjusted earnings per share came up short, and the next-quarter outlook wasn't overly optimistic.

Now what: Sometimes it's more important how you say something than what you're saying; CEO Gary Smith said that his company is taking market share in a period that's holding down sector rivals from JDS Uniphase (Nasdaq: JDSU) to Alcatel-Lucent (NYSE: ALU). Moreover, Ciena reported positive operating cash flows, which has been a goal of Smith's for the past two years. Driven by mobile computing and digital video, high-speed networking will be in serious demand for the next five to 10 years, and Ciena looks poised to capitalize on this outsized opportunity.

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