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 Chinese online game operator Changyou.Com Ltd (NASDAQ:CYOU) sank 10% this morning after its quarterly results and outlook disappointed Wall Street.

So what: The stock has been highly volatile over the past year on growth uncertainty, and today's Q1 results -- EPS of $0.82 blew out Wall Street but a revenue increase of 12% missed estimates -- coupled with downbeat guidance only reinforce those concerns. In fact, gross margin during the quarter fell 200 basis points over the year-ago period, suggesting that its licenses and, in turn, its competitive position, are getting more expensive to maintain.

Now what: Management now sees a Q1 loss of $0.42-$0.30 per share on revenue of $174 million-$180 million, well below the Wall Street consensus of a $1.04-per-share profit and on a top line of $199 million. "We ended fiscal year 2013 with revenues across each of our businesses reaching new highs in the fourth quarter, and solid growth in our top-line results for the full year," said CFO Alex Ho, who also announced his resignation to start a new business. "With the consistent rich cash inflows from our existing businesses, we are in a good position to continue investments in mobile games and new software applications of our platform initiative." More importantly, with the stock now off more than 35% from its 52-week highs, it might be an opportune time to buy into that bullishness.