I could understand if Apple (Nasdaq: AAPL) shares got a peeling from reporting bad numbers. It would even make sense if management's outlook sounded gloomy. But let the iCompany report the usual blowout holiday quarter and guide much the same way it always has -- and investors run for the hills, crying "uncle!"

Why, oh why?
Of course, the report came at the tail end of a seriously stressed-out trading day, on which the nation's top financial brass took desperate measures to try and prevent an outright recession. But much like fellow entertainer Walt Disney (NYSE: DIS) -- where Steve jobs holds a board seat -- and "sin stocks" Altria (NYSE: MO) and Diageo (NYSE: DEO), Apple doesn't really swing along with the larger economy. Come hell or high water, people still want their Mickey Mouse, a pint of Guinness, some Camel smokes -- and a few iTunes tracks. It's all about brand loyalty, and Apple has that in spades.

The next logical explanation would be the company's third-quarter guidance falling below the current Wall Street consensus. Only, you're forgetting about Apple's penchant to underpromise and overdeliver.

This first quarter was the exception to that rule, as management's sales and earnings forecasts came in a bit above the analyst estimates at the time, only to blow them both out of the water. In each of the previous seven quarters, the Jobs gang guided below Street numbers on both counts, and then proceeded to deliver impressive punchlines to all of those inside jokes. And all told, this was the seventh quarter in a row where earnings looked sharper than the pre-guidance analyst estimates, too.

iSaturation
There's only one more semi-reasonable explanation for the price drop: slowing iPod growth. Twenty-two million music players sold meant a mere 5% unit growth over the previous holiday quarter. It's a deceiving figure, though, because the average iPod sold for $180 this quarter, compared to $162 a year ago. Thank the shiny new iPod Touch -- basically an iPhone without the phone -- for that trick.

It's also possible that iPhone sales cut into the craving for pure music players, to the tune of 2.3 million units sold. Management spent much of the conference call fending off these concerns from worried analysts, saying that the iPod line is morphing into "the first mainstream WiFi mobile platform" rather than just a music player, and that it was still too early to tell if the phones were eating into other gadget sales. Either way, CFO Peter Oppenheimer claimed a stable vise grip on the U.S. music player market and gain on the competition in Europe and Asia. You make that cannibalization call, Fool.

What's the damage, Captain?
So a 13% drop brought the shares back to about $135 a pop, on top of a 21% slide since the start of the new year. Cry me a river. It's a throwback all the way to July 2007 -- six entire months ago. If your position is any older than that, you're still in the green here. And there's no reason to believe that the stock price will stay down at these levels for very long. A trailing P/E ratio around 34 is darn cheap for a company that can deliver year-over-year growth like this:

Q3 2006

Q4 2006

Q1 2007

Q2 2007

Q3 2007

Q4 2007

LTM Earnings Growth

88.3%

49.8%

51.9%

61.9%

67.1%

75.8%

I have been critical of Apple as an investment, based on a lofty valuation and the fact that the company lives and dies with Steve Jobs. While the company is still built around the man, the myth, the turtleneck, I'm less concerned about valuation right now. As of this moment, it looks like growth finally caught up to the price, and then left it eating dust.

You still have to believe in the brand, and assume that there isn't a stray meteorite on its way with Jobs' name on it, but given those fairly reasonable assumptions, there's really no reason not to buy Apple stock today. Well, aside from trading restrictions imposed by our Foolish disclosure policy, of course. But that's another story that probably doesn't apply to you.

Further Foolishness:

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Fool contributor Anders Bylund owns shares in Disney and Netflix, but holds no other position in any of the companies discussed here. He also doesn't own iAnything. You can check out Anders' holdings if you like, and Foolish disclosure always looks good in a smooth, white plastic case.