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 outsourcing services provider ExlService Holdings (Nasdaq: EXLS) were soaring today, gaining as much as 18% in intraday trading after announcing first-quarter results.

So what: There's no guesswork needed to figure out why ExlService's stock is firing on all cylinders today. For the first quarter, the company reported $0.33 in adjusted earnings per share, which was up 38% from a year ago and easily topped the $0.25 that Wall Street expected. The top line was similarly positive, as revenue gained 34% from last year and also topped analysts' estimates.

Now what: While strong results from the quarter can get investors excited, hints about a better future can make them go bananas. In ExlService's earnings press release, management boosted its outlook for all of 2011. Thanks in part to the just-announced acquisition of Outsource Partners International, ExlService increased its 2011 revenue guidance from a range of $295 million to $305 million to a range of $347 million to $355 million. The company is keeping its operating margin guidance fixed, so the higher revenue should translate into higher profit as well.

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