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 casino operator Boyd Gaming (NYSE: BYD) surged as much as 15% in intraday trading Tuesday after Merrill Lynch upgraded the stock to "buy" from "underperform."

So what: Citing a Las Vegas market that seems poised for a multiyear cyclical recovery, Merrill offered a $16 price target with the upgrade, representing 45% upside to Boyd's closing price Monday. Not surprisingly, Merrill also upgraded MGM Resorts (NYSE: MGM), whose shares are up 5% today, on those same Sin City tailwinds.  

Now what: I'd remain cautious about buying in right now. Boyd certainly stands to benefit from a continuing recovery in Las Vegas, but Asia-exposed casinos like Las Vegas Sands (NYSE: LVS) and Wynn Resorts (Nasdaq: WYNN) still strike me as tastier opportunities. And with lower debt-to-equity ratios than Boyd, they both seem like safer bets, as well.

Interested in more info on Boyd? Add it to your watchlist.

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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