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 ACI Worldwide (NASDAQ:ACIW) have skyrocketed today by as much as 17% after the company reported earnings and reaffirmed guidance.

So what: Revenue in the quarter totaled $155.1 million, an increase of 38% over last year, although more than all of this gain was attributed to the acquisition of S1. Earnings per share was $0.29, which was slightly worse than the $0.31 per share profit that the Street was targeting.

Now what: The company reaffirmed full-year guidance, expecting adjusted revenue to be in the range of $706 million to $716 million, and adjusted EBITDA of $188 million to $193 million. On a GAAP basis, 2012 should see sales of $683 million to $693 million. During the quarter, ACI also completed its acquisition of Distra, which will provide additional cross-selling opportunities.

Interested in more info on ACI Worldwide? Add it to your watchlist by clicking here.

Fool contributor Evan Niu, CFA, has no positions in the stocks mentioned above. The Motley Fool has no positions in the stocks mentioned above. 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.