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 Nanometrics Incorporated (NANO) popped more than 10% during Wednesday's intraday trading, then settled to close up 7% after the company turned in better-than-expected fourth quarter earnings. 

So what: Quarterly revenue rose 18% year over year to in at $46.2 million, which translated to adjusted earnings of $0.04 per diluted share. Analysts, on average, were looking for a loss of $0.01 per share on sales of just $44.88 million.

For the current quarter, Nanometrics expects revenue to be in the range of $48 million to $54 million, which should result in non-GAAP earnings of $0.01 to $0.13 per share. Analysts were modeling Q1 earnings of $0.08 per share on sales of $50.6 million.

Now what: The midpoint of their earnings guidance came in slightly below expectations, but management explained that the miss was primarily due to a shift in timing of R&D program spending from Q4 into Q1.

That's fair enough, but while shares don't look particularly expensive trading at 14.6 times next year's estimated earnings, I'm still not quite compelled enough by Nanometrics' growth to want to buy shares now. At the very least, I think investors would do well to add this one to their watch lists to keep tabs on the company's progress.