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 staffing firm On Assignment (Nasdaq: ASGN) jumped 10% briefly in early trading after the company reported earnings.

So what: Revenue nearly doubled from a year ago to $283 million, and net income was $8.5 million, or $0.28 per share after adjusting for acquisition costs. Analysts only expected earnings per share of $0.23, so the market is cheering the better-than-expected results.

Now what: Excluding the Apex Systems acquisition, revenues were still up 28%, so the core business is still very healthy. Management is also expecting conditions to improve in the third quarter, with revenue guidance of $382 million to $388 million and expected earnings per share of $0.28 to $0.31. With these growth numbers, I think the company's 13 forward P/E ratio is a good value for investors and shares can move higher from here.

Interested in more info on On Assignment? Add it to your watchlist by clicking here.