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 IPG Photonics (NASDAQ:IPGP) have lost 10% of their value today after the company disappointed Wall Street with weak earnings.

So what: IPG's first-quarter report showed revenue of $141.9 million and earnings of $0.67 per share. Although both showed respectable year-over-year growth, analysts were looking for $150.2 million on the top line and $0.70 in EPS. IPG's guidance for the second quarter now clocks in at $155 million to $165 million against a $162.1 million consensus, with EPS guidance ranging from $0.72 to $0.82, against Wall Street's $0.78 target.

Now what: This drop might not be such a bad thing. At a 20.6 P/E, IPG is valued like many other slow-growth companies when it's continuing to post double-digit growth in its fundamentals. Both top- and bottom-line guidance show more opportunity ahead, and the company's core materials processing business is up 29% year over year. I would keep my eye on this stock after the drop today. Just because analysts got a little overly optimistic doesn't mean that the company's fundamentals aren't strong.

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