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 oil refiner Tesoro (NYSE: TSO) fell by 10% today as oil put pressure on the shares.

So what: Oil was up as much as 3.7% today and has hit the entire refining sector hard. Western Refining (NYSE: WNR), Marathon Petroleum (NYSE: MPC), and Tesoro all fell more than 10%.

Now what: Oil has jumped dramatically over the past week, and unless gas prices rise, refiners will be stuck in the middle. With the exception of the collapse of Europe -- which, considering its ineptness so far, may be a possibility -- I have been saying for some time that oil was bound to rise, and the move in the past week has proven that to be true.

I'll stay away from refiners right now; I'd much rather have exposure to higher oil prices through oil and gas explorers.

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Fool contributor Travis Hoium does not have a position in any company mentioned. You can follow Travis on Twitter at @FlushDrawFool, check out his personal stock holdings or follow his CAPS picks at TMFFlushDraw.

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