Apple's real earnings problem: The forecast

Great opportunity to get into AAPL: Pro

Apple CEO Tim Cook said the company had an "amazing quarter." Unfortunately for him, investors care much more about the forecast.

The iPhone maker predicted fiscal fourth-quarter revenue of $49 billion to $51 billion, trailing the $51.1 billion average analyst estimate in a Thomson Reuters survey.

The company had little margin for error after a 39 percent jump in the stock price over the past year. Apple shares dropped 7.3 percent in after-hours trading Tuesday to $121.18.

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Third-quarter numbers mostly beat estimates. The Cupertino, California-based company sold more iPhones and Mac computers than expected, leading to total revenue of $49.6 billion, above the $49.3 billion average estimate. Net income of $1.85 a share topped predictions for $1.81.

The problem is that estimates had been creeping up based on bullishness for iPhone and Apple Watch sales.

Apple didn't break out numbers for the watch. And the iPhone, while topping most estimates with 47.5 million units, fell short of the more bullish predictions of late that called for more than 50 million units.

The tech giant didn't provide additional color into the fourth quarter, aside from its forecast, so investors are left to guess where the softness lies. They likely got some clarity during the conference call.