File this under the heading: "The good news is that the bad news wasn't as bad as some people had feared." When it comes to casino stocks, however, long-term investors will need more than less bad news.

Recently, Las Vegas casino headliners MGM Mirage (NYSE:MGM) and Wynn Resorts (NASDAQ:WYNN) each released quarterly results, falling short of Wall Street's expectations. Las Vegas Sands (NYSE:LVS) produced quarterly earnings that modestly beat the consensus forecast.

So, what happens? Shares of each company, especially deep-in-debt MGM Mirage and Las Vegas Sands, jumped sharply on heavy volume. Las Vegas Sands closed May 5 in double digits for the first time since Nov. 5. MGM Mirage closed May 5 in double digits for the first time since Jan. 14.

Meanwhile, a trio of companies without any operations in Las Vegas managed to produce healthy, Wall Street-beating results in late April to win the applause of investors. Reports by Ameristar Casinos (NASDAQ:ASCA), Pinnacle Entertainment (NYSE:PNK), and Penn National Gaming (NASDAQ:PENN) have illustrated why better gains can be found away from their Las Vegas peers.

Of course, the big Las Vegas-focused operators have properties elsewhere. But here's one sobering thought: Shares of MGM Mirage, Las Vegas Sands, and Wynn Resorts still aren't in the same ZIP code, or even the same time zone, as their 52-week highs.

For investors, erratic stock movements and high volume should signal red flags, or at least amber lights, for some of these companies. Debt renegotiations, financing agreements, or stock infusions have provided some hope. But are they sustainable?

Look out for the lenders
SEC filings for some casino companies should remind old-time movie buffs of the Perils of Pauline, a silent film produced so that each chapter ended with a cliffhanger to keep audiences coming back for weekly installments. (For younger investors, the TV series 24 should serve as a reference.)

MGM Mirage's cliffhangers are its negotiations with lenders, each extending waivers and/or revising terms for the company's $14.4 billion in debt versus a $1.4 billion cash balance.

In a recent filing with the Securities and Exchange Commission, MGM Mirage said a deadline for complying with terms of a senior credit facility had been pushed back to June 30 from March 31. That's the news, along with a recent announcement about completing the financing for its giant CityCenter project in Las Vegas, that encourages investors these days.

Last month, Wynn Resorts renegotiated a credit agreement, extending some covenants to June 2011 and extending maturity dates on part of the debt to July 2013 from August 2011. Wynn Resorts now has $4.5 billion in long-term debt and $1.3 billion in cash.

Las Vegas Sands hasn't announced any quarterly cliffhangers recently. However, it has $10.4 billion in total debt and $2.76 billion in unrestricted cash.

Room to maneuver
In addition to checking debt, investors must mind the till -- the revenue not only from gambling but also from food, entertainment, and hotel stays.

For the hotel component, an important indicator is RevPAR, which sounds like the home planet of the Coneheads. It stands for "revenue per available room" and it's based on multiplying a hotel's occupancy rate by the room rate.

Let's use one example. MGM Mirage said occupancy rates for its Las Vegas Strip operations were "unusually low" in January, better in February, and at a "normalized" level of about 95% in March. But it cut its Las Vegas room rates for the quarter, resulting in a 34% drop in RevPAR versus the year-ago quarter. That played a key role in total room revenue falling to $355 million from $518.7 million.

Now imagine this scenario playing out among all Las Vegas casino operators -- big and small, public and private -- as some companies continue their Las Vegas expansion plans.

The Las Vegas Sun recently reported that more than 12,000 rooms could be added this year, assuming that the MGM Mirage CityCenter complex and the privately held Fontainebleau hotel/casino open on schedule. The headline "Capacity Crunch" needs no elaboration. Last month, the Fontainebleau's owner sued 11 lenders after a financing agreement was canceled, raising questions about the construction's progress.

The big picture
In the context of casino operators' debt and the recession's impact on consumer spending, Las Vegas expansion plans raise two questions: If you build it, will they come? And if they come, will they spend?

Meanwhile, the overall numbers still don't look good. The Las Vegas Convention and Visitors Authority said first-quarter visitor volume was down from the year-ago quarter. So was hotel occupancy, the average room rate, convention attendance, the number of conventions, average daily auto traffic, and number of airline passengers. Gambling revenue on The Strip was down 16.9% and down 14.7% for all of Clark County. The March 2009 versus March 2008 figures were equally unsettling.

Amid this news, some people were brave enough to buy MGM Mirage and Las Vegas Sands shares at microscopic levels. Congratulations to the traders. As for the longer-term investors, casino companies with big holdings in Las Vegas still appear to be vexing.

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Fool contributor Robert Steyer doesn't own shares of any companies cited in this article. Ameristar Casinos is a Motley Fool Hidden Gems recommendation. The Motley Fool has a disclosure policy.