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: In a way, I suppose Kforce (Nasdaq: KFRC) shareholders should feel honored today. On the one hand, their company lost 32.5% of its market cap. On the other, at least it topped the charts of the Nasdaq's biggest losers in doing so. If yer gonna go down, go down in flames and make a spectacle.

So what: What went wrong? In a word, earnings. Kforce announced that it earned $0.17 per share in Q2, a 31% increase over last year's Q2 on just an 11% rise in revenues. Problem was, Wall Street wanted to see $0.19 per share.

Now what: Kforce intends to miss earnings again in Q3. As part of its report yesterday, management announced that it expects to collect about $280 million in revenues for the current quarter and earn roughly $0.18 thereon. If it's right about those numbers, Wall Street will be very displeased indeed. Current analyst estimates call for more than $290 million in revenues and $0.23 per share in earnings.

Perversely, this may turn out to be good news for investors. Post-sell-off, Kforce shares now sell for just 14.5 times earnings. Whatever happens in this current quarter, over the longer term, analysts still believe that Kforce is capable of growing earnings at better than 30% per year (and remember, Kforce did just that in Q2). I have to say -- the resulting PEG ratio of less than 0.5 on the stock looks awfully attractive. If you can bear the sight of your portfolio today, you might want to take a look at the "buy" button.

Willing to give Kforce some more time to prove itself? Add it to your Fool Watchlist.