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 Imperva (NYSE:IMPV) are up by 7% today, after an opening-bell spike took the stock as much as 9% higher, thanks to a surprise earnings beat. The market has apparently shrugged off severely negative EPS guidance in favor of celebrating today's victory.

So what: Imperva reported $31.8 million in revenue and an adjusted profit of $0.06 per share, which came in well ahead of Wall Street's expectations of $0.02 per share. For the current quarter, Imperva's management anticipates $27.0 million to $27.5 million in revenue, which will result in an adjusted net loss of between $0.09 and $0.11 per share. The top-line estimate matches Wall Street's $27.2 million expectation, but the bottom-line guidance was far below analysts' consensus estimate of a $0.01 loss per share. For the full year, Imperva projects $131 million to $135 million in revenue, resulting in $0.15 to $0.21 in EPS. Full-year revenue guidance surpassed Wall Street's $127.9 million consensus, but in EPS terms, Wall Street's $0.26 projection handily beats Imperva's own numbers.

Now what: Imperva could provide another set of surprises this year, as it also expected $0.02 in EPS this quarter in its guidance from late 2012. However, this is not the sort of report that, on the whole, should merit a major pop. I'd stay on the sidelines until further details emerge.

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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 news and insights.

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