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 Affiliated Managers Group, (NYSE:AMG) finished Tuesday with an 8.5% gain after topping out with a peak pop of over 10% in late afternoon trading. The asset management company's first-quarter earnings, released before the opening bell, impressed  investors despite mediocre revenue, and Affiliated also rode positive sentiment in the wake of its announcement that it would acquire a majority stake  in Veritas Asset Management.

So what: Affiliated's first-quarter revenue rose 18% year-over-year to reach $593.1 million, but analysts had expected $612.2 million. However, investors were willing to look past this "weakness" in light of Affiliated's earnings of $2.48 per share, which beat Wall Street's expectation of $2.37 in EPS. Affiliated also announced its majority stake in Veritas this morning. The London-based firm manages roughly $17 billion in assets around the world, which is modest compared to Affiliated's $594 billion in assets under management (AUM) -- a 28% year-over-year increase in AUM -- but the company has also recently invested in EIG Global Energy Partners and River Road Asset Management.

Now what: Affiliated has grown quite a bit  in recent years -- investors have a three-bagger on their hands since late 2009, and EPS is up over 350% on that time frame as well. Despite this growth, Affiliated's valuation is near its lowest level of those five years, and by all indications, the company's growth isn't over yet. Dig deeper and you might find a worthwhile stock at a fair price, even after today's big pop.

Alex Planes has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. 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.