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 independent oil refiner Western Refining (NYSE: WNR) rose 15.5% in intraday trading today after a Wall Street analyst upgraded the stock.

So What: Because Western Refining implemented restructuring initiatives that involve heavy deleveraging and refocused its portfolio on higher-return markets, Morgan Stanley upgraded it to overweight with a $9.00 price target. With Western Refining poised to cut its debt load by more than half in 2011, Morgan Stanley also believes the shares deserve to trade at less of a discount to rivals Holly (NYSE: HOC) and Frontier Oil (NYSE: FTO).

Now What: Even with today's pop, there's still about 40% worth of upside to Morgan Stanley's $9.00 price target. Of course, when you couple Western Refining's restructuring efforts with the fact that even integrated giants like ExxonMobil (NYSE: XOM), Chevron (NYSE: CVX), and ConocoPhillips (NYSE: COP) all have strengthening refining margins, the stock has some serious multibagger potential, to boot. I'd feel uncomfortable about jumping in today, but any pullback should be considered a long-term entry point.

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

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Try any of our Foolish newsletter services free for 30 days.

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