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 refiner Delek (NYSE: DK) fell as much as 10% in early trading after the company said it would miss earnings expectations.

So what: After the market closed yesterday, the company said it expected to report a loss of $0.10 to $0.20 per share from continuing operations in the fourth quarter. Analysts had expected earnings of $0.59 per share, so the results will likely be very disappointing when they're released on March 7.

Now what: A seasonal decline in asphalt prices as well as high oil prices were the major contributors to the loss. I don't see oil falling anytime soon, so the pressure could continue well into the future. I'm not seeing any buy signals today, but keep an eye on asphalt prices, which could drive better results in the future.

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