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 medical-device manufacturer Cyberonics (Nasdaq: CYBX) took flight today, rising more than 11% in intraday trading as investors reacted to the company's fiscal-second-quarter earnings.

So what: It's rare that a 50% drop in net income isn't a reason for investors to be seriously worried. But for Cyberonics, hefty tax benefits threw off both the recently completed quarter as well as the same quarter a year ago. Revenue and operating income for the company were actually up 17% and 41%, respectively, versus last year as the company's VNS Therapy System continued to show healthy gains in the U.S. market. Adjusted earnings per share of $0.26 slightly edged out the $0.25 expected by Wall Street analysts.

Now what: It was the look ahead, however, that likely got investors really jazzed about Cyberonics' report. After a better-than-expected first half of its fiscal year, the company decided to bump up its full-year guidance, taking the midpoint of its revenue forecast from $186 million to $188.5 million. Operating income expectations were boosted from a midpoint of $43.5 million to $46.5 million. The new operating profit guidance represents 26% growth over fiscal 2010's tally -- a growth rate the company will likely have to at least sustain to justify the stock's current valuation.

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