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: Teradyne (NYSE: TER) dropped 15% in intraday trading today after the company provided a disappointing second quarter outlook  and gave reason to believe that EPS expectations are too high in general.

So what: Management expects non-GAAP EPS of $0.38 to $0.44 for the current quarter, compared to the consensus estimate of $0.44. The company guided EPS and revenue for the quarter below year-earlier levels, even though it stated 2011 is off to a strong start and total orders were up 30% in the first quarter.

Now what: First quarter EPS of $0.39 beat the consensus estimate of $0.37 with better than expected revenue. But a gain on the disposal of discontinued operations contributed about $0.10 to EPS for the quarter. Without that gain, first-quarter EPS would have been below the year-earlier level of $0.33.

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