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: Boyd Gaming (NYSE: BYD) saw its shares surge 10% in intraday trading Wednesday after Barclays upgraded the casino operator from "equal weight" to "overweight."

So what: Citing better-than-expected results from its Borgata casino in Atlantic City, N.J., as well as a Las Vegas market that seems poised to bounce in 2011, Barclays also offered a $13 price target for Boyd's shares. At the time of publication, Boyd's volume had already more than doubled its average, so Mr. Market is clearly taking the upgrade to heart.

Now what: Fools, however, know to take analyst opinions with a grain of salt. While Boyd is well-diversified here in the U.S. (15 properties in five states), I still prefer Macau-focused casinos like Las Vegas Sands (NYSE: LVS), Wynn (NYSE: WYNN), and Melco Crown (Nasdaq: MPEL) as more attractive bets in the space. When you consider that Boyd is now up 50% over the past three months alone, the decision is even that much easier.

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