Apple Inc's stock is just a couple of dollars shy of its all-time high, and any misstep the maker of iPods, iPhones and Macintosh computers reports on Monday could give investors an excuse to cash out.

The stock, which has doubled so far this year, has been on a relentless march upward for the past month despite a barrage of criticism from die-hard Apple fans over draconian controls on the iPhone that prevent them from installing software from outside developers.

Apple's quarterly earnings report next Monday could be a catalyst for further gains, but a slip, no matter how small, could give investors an excuse to cash out, analysts said.

Given Apple's high valuation, we think a shortfall in any one of its three businesses or outlook could send the stock tumbling, Bernstein analyst Anthony Sacconaghi said in a recent note.

We believe Apple's current valuation is justifiable, but not especially compelling, Sacconaghi wrote. He has a price target of $175 on Apple shares.

Sacconaghi was one of nine analysts who have raised their price targets on Apple since September 12, citing strong sales of iPods and Mac computers. Over that time, the stock has risen 24 percent.

Having gained $2.60, or 1.6 percent, to close at $169.58 on Tuesday, the stock is nearing not only its high of $171.88, set last Thursday, but also the increased price targets, which range from $175 to $190.

Morgan Stanley analyst Kathryn Huberty said Apple may show better-than-expected profitability thanks to falling component costs that have lifted results in the past few quarters.

Huberty reckoned gross margin could be as high as 31.6 percent, well above the company's forecast of 29.5 percent.

If investors keep betting on faster growth and good product buzz, Apple shares could trade at up to 40 times expected 2008 earnings per share, Huberty said.

That multiple would value Apple shares at $181, based on the $4.53 per share that is the average forecast on Reuters Estimates. If profits hit the upper range of estimates, the shares could blow past the $200 mark.

CHANGING BUSINESS MODEL

For its fiscal fourth quarter ended September 30, Apple is expected to show a profit excluding items of $751.7 million, or 82 cents per share, on revenue of $6 billion, according to Reuters Estimates. That profit figure is about a third higher than what Apple reported a year ago.

But with key aspects of the iPhone business still under wraps, such as how much of service provider AT&T Inc's fees go to Apple's coffers, analysts say the stock's performance is hard to predict.

While historical ranges are important to consider, they only provide one perspective and should be taken in context of Apple's changing business model, Huberty wrote.

As the iPhone shakes up the cell phone market, iPods are expected to keep dominating the portable music industry thanks to a recent overhaul of that line.

Both products are helping drive sales of Macs, which jumped by about a third in Apple's fiscal third quarter to nearly 1.8 million machines.

But the strong performance masks growing anger over Apple's campaign to prevent iPhone users from installing software from third-party developers or making calls on a cellular network other than that of AT&T.

The discontent has even spilled over into the courtroom, with the filing of a couple of class-action lawsuits, legal action that attempts to seek damages on behalf of a larger group of people -- in this case, iPhone users.

Many consumer product companies, including Apple rivals, face such legal action, but the lawsuits reflect deepening discontent toward a company that has traditionally stirred passionate support among customers.

It has more to do with Apple entering a new market with a lot of new rules, Tim Bajarin, head of Silicon Valley consultancy Creative Strategies, said of the company's strict iPhone controls.

They are trying to play by as many rules as put in front of them and at the same time trying to innovate. It's a tough place to be sometimes because if you are first in any area you almost always have arrows in the back, Bajarin said.

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