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 professional community operator Dice Holdings (NYSE:DHX) plunged 13% after its quarterly results and outlook disappointed Wall Street.

So what: The stock plunged three months ago after posting a 16% drop in quarterly earnings, and today's Q3 results -- EPS of $0.12 missed Wall Street's estimates by $0.01 while revenue rose just 9.6% -- coupled with downbeat guidance only reinforces the worrisome trend. In fact, adjusted EBITDA margins during the quarter slipped 620 basis points to 33.9%, suggesting that Dice's competitive position continues to weaken at a rapid rate.

Now what: Management now sees Q4 net income of $7.4 million on revenue of $52.9 million, while Wall Street was forecasting a top line of $54.2 million. "We have a lot of things to do, but the core tenets of our strategy, focusing on targeted markets and delivering efficient recruiting solutions, are not changing," said CEO Michael Durney. "We are putting a tremendous amount of energy and effort to reposition for growth, which we will continue to pursue both organically and through acquisition." Given Dice's still-speculative business model, worrisome operating trends, and increasingly fierce competition, however, I wouldn't be so quick to buy into that turnaround talk.