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 clinical data specialist Medidata Solutions (Nasdaq: MDSO) were looking sickly today, falling as much as 22% in intraday trading after the company reported fourth-quarter earnings.

So what: Medidata's fourth quarter was actually very solid. Net revenue for the quarter was $47 million, up 26% from last year and above the $44 million estimate from Wall Street analysts. Margins increased as well, making the company more pro fitable and leading to a doubling in net income. Pro forma, non-GAAP earnings per share were $0.29, which also topped analysts' estimates.

However, the company's outlook didn't live up to what investors were hoping for. The National Cancer Institute terminated its contract with Medidata, an undesirable turn for the company that will cost it $4.8 million in revenue in 2011. The company projected revenue for the year at $180 million to $188 million, while analysts had their sights set on $188 million.

Now what: Is the NCI contract termination just a one-time set-back for Medidata? If so, the reaction to today's news may be a bit harsh since, excluding the NCI revenue loss, the company's 2011 revenue growth would have been 16%, which is in line with the company's growth target. Of course, with shares trading at 19 times analysts' previous expectations for 2011 earnings per share even after today's sell-off, it's obvious that investors had high hopes for the company.

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Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or on his RSS feed. The Fool's disclosure policy prefers dividends over a sharp stick in the eye.