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 Bona Film Group Limited, (NASDAQ: BONA) were landing on the cutting room floor today, falling as much as 14%, and finishing down 6% after a disappointing fourth-quarter earnings report.

So what: The vertically integrated Chinese film company said revenues in the quarter slid 20%, to $42.8 million, though earnings per share improved substantially from a loss of $0.09 to $0.01 per-share profit. Analysts had expected a $0.02 profit, however. CEO Yu Dong said the company had "delivered solid results in 2013, driven by the release of 14 films domestically that generated an approximate 10% market share of domestic box office receipts." 

Now what: Bona Film has been a volatile stock during the past year, so I wouldn't be too concerned with today's drop. For the first quarter, the company expects a per-share profit of $0.02-$0.03, though analyst estimates were unavailable for comparison. Still, a 10% market share is nothing to sneeze at, especially for a small company like Bona in a growing market. The studio also has prominent backers including 21st Century Fox, and the Chinese conglomerate Fosun, indicating that it is well staked should it need financial help. Long term, I expect shares to move higher.