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 Forest Oil Corp. (NYSE: FST) dropped 11% in intraday trading today after fourth-quarter adjusted EPS of $0.44 fell short of the consensus estimate of $0.47 and management lowered its 2011 volume forecast. 

So what: Revenue of $124 million was 10% below the consensus forecast, pressured by declining prices. Adjusted EPS, EBITDA, and cash flow all fell from the year-ago quarter because of a decline in prices and a reduction in realized gains on derivatives.

Now what: Sales volume guidance for 2011 was lowered by 4% while per-unit production cost guidance was reiterated with no change. No EPS guidance was provided, but earnings are sensitive to derivatives and foreign exchange gains/losses in addition to volatile natural gas and oil prices. With the stock trading at a forward P/E ratio of 22.2 and EPS estimates likely to come down, the risk does not seem to justify the reward.

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

Fool contributor Cindy Johnson does not own shares of any company named above. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.