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 Syntel (NASDAQ: SYNT) sank today by as much as 11% after the company revised  its full-year guidance.

So what: The company said that one of its customers is cutting back spending temporarily through the end of 2012, which is leading Syntel to reduce its full-year estimates. Revenue for 2012 is now expected in the range of $720 million to $722 million, which should translate into earnings per share of $4.26 to $4.29.

Now what: That's down from Syntel's prior  guidance of $730 million to $735 million, so the midpoint of guidance has been decreased by $11.5 million. The company has also previously been targeting $4.36 to $4.40 in earnings per share this year, putting it on track to top the analyst forecast of $4.36 in earnings per share on $729.1 million in sales. Today's revision means the company will fall short of investor expectations for 2012.

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