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 semiconductor fabrication equipment maker FSI International (Nasdaq: FSII) took an overnight header to the tune of as much as 28% before paring the losses to 13% at the time of writing this article.

So what: FSI's first-quarter report missed analyst expectations by a relatively thin margin, but guidance for the next quarter is seen as very disappointing. It's another case of lumpy results for a small company causing a market panic: Management points to the timing of a few large orders as the reason for its timid outlook.

Now what: I wouldn't take FSI's cautious outlook as a sign that major customer Samsung or Intel (Nasdaq: INTC) are cutting down on their infrastructure investments, particularly since Intel only recently announced an $8 billion plan for retooled and expanded manufacturing facilities. FSI rivals Lam Research (Nasdaq: LRCX) and Semitool (Nasdaq: SMTL) were not affected by FSI's report, which is another sign that this issue is FSI's own and not a sector effect. As usual, the market hates unpredictable results, and you would be well-advised to look at this drop as an opportunity to see if this stock fits into your own portfolio.

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