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 household name Xerox (NYSE: XRX) have tanked today by as much as 13%, after the company reported fourth-quarter earnings.

So what: Revenue in the quarter came out to just under $6 billion, a tad shy of the consensus of $6.07 billion, while profit was right on target with the expectations of $0.33 per share. For the full year 2011, revenue totaled $22.6 billion with a $1.3 billion net profit.

Now what: While the next quarter's projected earnings per share of $0.21 to $0.24 weren't particularly impressive, the real devil was in the details. Xerox said that the increase in services signings continues to weigh on gross margins as the company makes initial investments to land new contracts. On the bright side, Xerox's board recently notched up its share repurchase authorization by $500 million to more than $1.3 billion, leading to its expectation of repurchasing between $900 million and $1.1 billion in shares this year.

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Fool contributor Evan Niu holds no position in any company mentioned. Click here to see his holdings and a short bio. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.