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 Advanced Energy Industries (NASDAQ:AEIS) fell 13% early Tuesday and then recovered to close down around 6.5% after the power conversion technology specialist announced that its CEO of three years, Garry Rogerson, has decided to step down.

So what: Only a few weeks ago, Advanced Energy shares plunged 21% in a single day after the company released mixed first-quarter results and disappointing forward guidance. Still, Rogerson elaborated, "Having made enormous strides on our strategic plan to drive revenue growth, expand margins and increase cash generation, I believe this is a great time to begin a new chapter -- both for our company and for me."

Now what: But the market obviously isn't as optimistic about seeing more management turnover right now. Remember, one of Advanced Energy's co-founders, Douglas Schatz, already retired from the company's board in March, albeit admirably citing a desire to spend more time handling his charitable foundations. Nonetheless, the move resulted in a downgrade today from analysts at Needham, who noted concerns that these high-level departures over such a short time period could cause major disruptions at Advanced Energy.

Even so, note that Rogerson has no intention to leave the company in a lurch and will continue to serve as CEO until a successor is found. In addition, it appears much of this pessimism is priced in, with shares currently trading around 9.6 times next year's estimated earnings. Management turnover or not, I still think Advanced Energy is worth a look for patient, long-term investors.

Steve Symington and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.