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 PDF Solutions (NASDAQ:PDFS) are up 9% today, after reporting preliminary earnings that came in ahead of expectations.

So what: PDF's fourth quarter showed $23.8 million in revenue, a 6% gain over the prior quarter, and a 35% increase over the year-ago quarter. On an adjusted basis, the company reported $0.24 in earnings per share, which bested the $0.22 per share that PDF's one analyst expected. This was a 14% increase from the previous quarter, and a doubling of the year-ago quarter's $0.12 result.

Now what: PDF has been rising all year, and has more than doubled in the past 52 weeks. The company did not offer guidance for the upcoming year, but the Street seems happy with this current performance. After the update, PDF's P/E is around 28 on a GAAP basis, which is in line with its average over the past four months or so. If these growth rates continue, PDF might be worth a closer look.

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Fool contributor Alex Planes holds no financial position in any company mentioned here. Add him on Google+, or follow him on Twitter @TMFBiggles for more insight into markets, history, and technology.

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