At The Motley Fool, we poke plenty of fun at Wall Street analysts and their endless cycle of upgrades, downgrades, and "initiating coverage at neutral." While the pinstripe-and-wingtip crowd is entitled to its opinions, we've got some pretty sharp stock pickers down here on Main Street, too. (And we're not always impressed with how Wall Street does its job.)

Given this, perhaps we shouldn't be giving virtual ink to "news" of analyst upgrades and downgrades. And we wouldn't -- if that were all we were doing. Fortunately, in "This Just In," we don't simply tell you what the analysts said. We also show you whether they know what they're talking about.

Today, Wall Street likes the odds for casino stocks Las Vegas Sands (NYSE: LVS) and Wynn (Nasdaq: WYNN), but looks less enthused about DNA tester Sequenom (Nasdaq: SQNM). Meanwhile, analysts are at odds about the prospects for semiconductor stocks AMD (NYSE: AMD) and NVIDIA (Nasdaq: NVDA). Let's dig into the details.

The case for casinos
Investors in general are enjoying a green day on Wall Street this morning, but few more so than shareholders of casino stocks Las Vegas Sands and Wynn Resorts. Both stocks are up this morning on the heels of positive commentary out of JPMorgan Chase -- Sands a bit more than Wynn, which is only to be expected, as the analyst hiked its price target on the former by 11%, and the latter just 3%. But why is JP enthusiastic about them at all?

As reported on StreetInsider.com, JP has hiked its target prices on the stocks based on its response that "the Macau gaming market will experience a rebound in growth, which will serve as a likely catalyst for positive estimate revisions." JP sees "continued mass market growth ... a slight acceleration of credit by junkets to VIP patrons," and the potential for easier lending standards in China as all contributing to increased gambling activity in Macau. Overall, the analyst is projecting 11% growth in both 2013 and 2014. But is that enough to justify buying these stocks?

After all, elsewhere on Wall Street, we know that analysts were already hoping to see 13.6% earnings growth at Wynn, and 20.1% at Sands over the next five years. Viewed in this context, mere 11% growth expectations hardly seem worthy of celebration -- the more so when you consider that Sands shares currently cost more than 27 times earnings, while Wynn fetches a nearly as-pricey 23-times multiple.

Sequencing Sequenom
On the plus side, at least Sands and Wynn are profitable. You can't say that about the recipient of today's featured sell rating: Sequenom. Yesterday, analysts at Piper Jaffray responded to Sequenom's $130 million debt offering by downgrading the stock to neutral. Today, Credit Suisse did Piper one better (or worse, depending on your perspective) by starting its coverage of Sequenom at underperform (Wall Street code for "sell").

But here's the weird thing: At the same time as Credit Suisse counsels selling the stock, it tells investors that in its opinion, Sequenom shares are worth about $4 apiece -- about 12% more than they cost today. And if that's the case, then why sell?

Maybe the answer is that there's no guarantee Sequenom will remain in business long enough to reach $4 -- not at the rate it's going. Over the past 12 months, this company burned through $88 million in negative free cash flow, a faster rate of cash-burn than we've ever seen at the company before, and on pace to mark the company's third straight year of accelerating cash losses. Granted, thanks to the debt offering that sparked Piper's downgrade, Sequenom now has enough cash to keep on burning it for another couple of years. But still -- sooner or later, the company's really got to figure out how to make some money for itself, if it's to be worth buying at any price.

Last and least
And finally, we come to the ratings you've all been waiting for: The semiconductors. This morning, two analysts took two different tacks on two different stocks, as FBR Capital dropped its price target on Advanced Micro Devices 20% to $6, while on the plus side, Roth Capital initiated coverage of NVIDIA at buy -- with a price target of $19, nearly 40% above where the stock trades today.

I'll cut right to the chase: I like both ratings, even if I suspect FBR cut too soon on AMD. Sure, AMD is technically "unprofitable" under GAAP accounting standards, but in the stock's defense, AMD did at least generate substantial free cash flow last year -- enough to give the stock a sub-7-times-FCF valuation at today's depressed prices. For a projected 10% grower like AMD, that's cheap, even if FBR doesn't think it's quite as good a bargain as it used to.

Meanwhile, NVIDIA retains all the earmarks of a bona fide bargain. Its price-to-free-cash-flow ratio is a low 13, below its projected growth rate. Plus, if you net out NVIDIA's $3.3 billion bank account (unlike AMD, NVIDIA is flush with cash), the EV/FCF ratio on this one drops down to an almost AMD-like 7.8. With NVIDIA's stronger growth prospects, that makes the stock one I want to own -- and one I do own -- and one I've publicly recommended on CAPS as well.

Circling back now to the stocks that we started with, though, perhaps you'd like to learn a bit more about Las Vegas Sands, and why it's a better (or worse) bargain than Wynn? Read our premium research report on the company, and find out. Just click here to get started.

Whose advice should you take -- mine, or that of "professional" analysts like JPMorgan, FBR, and Roth Capital? Check out my track record on Motley Fool CAPS, and compare it to theirs. Decide for yourself whom to believe.