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." Here, we'll show you whether those bigwigs actually know what they're talking about. To help, we've enlisted Motley Fool CAPS to track the long-term performance of Wall Street's best and worst.

And speaking of the best ...
If you're an iRobot (Nasdaq: IRBT) investor, you were probably less than pleased to see your stock drop yesterday, when the rest of the market was rising. I feel your pain. I'm a shareholder, too. But while disappointed in Brigantine Advisors' decision to downgrade iRobot (the move that precipitated the drop), I'm not surprised.

No major media outlets have details on why Brigantine downgraded the stock, but we don't need to guess at the analyst's reasoning. All we need to do is go back and review StreetInsider's write-up on Brigantine's buy rating from last month. After commending iRobot for exceeding expectations in 2010, Brigantine upped its predictions for fiscal 2011, writing: "we are now expecting revenues of $464.6 million and GAAP EPS of $0.99," and setting a target price of $32 on the stock. Want to take a guess what price iRobot hit Monday?

That's right: $32.01.

Mission accomplished
In other words, iRobot was 10.5 months ahead of schedule in hitting the goal Brigantine set a month and a half ago. Given this good fortune, it's not at all surprising that Brigantine decided to quit while it was ahead, "declare victory and go home." But that doesn't mean we should, too.

Why not? Consider: All other things being equal, a stock that's going to be worth $X in a year, and sells for $X today, probably doesn't have much profit potential left in it. But that's just the thing -- all things have not remained equal for iRobot. While some things have not changed, one thing in particular most definitely has.

What's changed …
Probably the most important development at iRobot over the past month and a half began in Japan, when a massive earthquake and tsunami devastated the Fukushima Daiichi nuclear complex, sending several reactors into meltdown. Many companies offered to help Japan in its crisis. General Electric (NYSE: GE) offered technical assistance to repair the plants it had built, FedEx (NYSE: FDX) and PotashCorp (NYSE: POT) pledged $1 million to Japan relief (offers quickly matched by another corporate behemoth -- Gwen Stefani), and Harley-Davidson (NYSE: HOG) donated $250,000 to the Red Cross.

I'm certain the Japanese appreciated all this help, but what did they actually ask for? Volunteers, to enter the highly contaminated reactors and begin assessing the damage. Robotic volunteers, that is -- from iRobot.

Increasingly, when disaster strikes, one of the first phone calls is to iRobot for help in dealing with the aftermath. iRobot Seaglider robo-subs went into the drink and began tracking the movement of the oil plume underwater after the BP (NYSE: BP) Gulf of Mexico disaster last year. And now that disaster has struck Japan, iRobot's proving its worth once again, sending four robots trundling into danger to spare human lives. And this won't be the last time.

According to the U.S. Nuclear Regulatory Commission, we're using the Fukushima disaster as an object lesson in what could go wrong at America's 104 nuclear power plants -- and what to do about it if it does. As far as prevention goes, this includes such steps as updating evacuation plans and ensuring plants are equipped with batteries to keep cooling systems operating in the event of a power disruption. But on the remediation side of things, I suspect the NRC is also pondering whether having a battalion of nuclear-fire-fighting robots on hand might not be a good idea, just in case things get particularly hairy. While there are plenty of heavy-industrial companies that might get tapped to build such 'bots, there's only one company I know of that now has actual, real-world experience using robots in this type of situation: iRobot.

... and what has not changed
I believe the leading role iRobot has taken in dealing with major disasters has positioned the company to expand into a new market. This, in a nutshell, is what has changed over the month and a half since Brigantine last told us to buy the stock. Now, here's what hasn't changed: iRobot is still cheap.

Not as cheap as it was back in February, granted. But with $36.6 million in trailing free cash flow, the stock still sells for only 22.5 times the amount of cash it generates in a year. Net out iRobot's sizable cash hoard, and the stock looks cheaper still, as its enterprise value-to-free cash flow ratio drops to just 17.5.

Foolish takeaway
With most analysts on Wall Street still predicting that iRobot will grow its business at a 24% annual clip over the next five years, I'd say both of these valuations suggest the stock remains buyable today. Just because Brigantine has already earned its iRobot profits, doesn't mean there's no money left to be made.

Fool contributor Rich Smith is putting his portfolio where his mouth is. Despite making a clean double on iRobot stock, he owns the stock still. You can find him on CAPS, publicly pontificating under the handle TMFDitty, where he's currently ranked No. 541 out of more than 170,000 members. The Motley Fool has a disclosure policy.

iRobot is a Motley Fool Rule Breakers recommendation. FedEx is a Motley Fool Stock Advisor choice and The Fool owns shares of FedEx.

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