Apple fans have a new day to circle on their calendars – September 9.

That's the day Apple is reportedly set to release its iPhone 6 models. The new phones are expected to have displays of 4.7 and 5.5 inches. The larger screens – something Steve Jobs said he wouldn't do – are in part due to demand in Asia, particularly China, where smartphones double as tablets.

(Watch: Apple iPhone event Sept. 9: Re/code)

But it's not just iPhone geeks, fan boysand conspicuous consumers waiting for the new iPhone. Apple investors are also keeping an eye on what a new iPhone can do for the stock. That's because if history is any indication, iPhone releases have meant serious money for shareholders. In fact, the history of Apple's six-month and 12-month returns after new releases shows that they've generally been quite positive for shareholders – with the exception of the iPhone 5.

But should investors jump into Apple based simply on the new iPhone release?

Erin Gibbs, equity chief investment officer at S&P Capital IQ, says iPhone releases alone aren't good predictors of how Apple will do. Instead, she believes investors should pay closer attention to revenue and earnings growth.

"They're looking at about 10 percent earnings growth for fiscal year '15 over '14, which includes all the sales for this particular release," Gibbs said. "There's a lot of expectations built into this release, because there's a feeling on Wall Street that people have been postponing purchases."

Failure of the new iPhone to deliver sales and take market share away from larger-screen smartphone sellers like Samsung could mean a pullback in Apple's stock warns Gibbs.

Though she does not hold Apple shares personally, the stock is among others in the $12 billion portfolios Gibbs advises for S&P Capital IQ. However, she doesn't believe investors should rush to buy the stock.

"It's trading at the top of its range, close to 15 times forward earnings," Gibbs said, who notes that it is still within its 10 to 15 times forward earnings range the stock has maintained since 2011. "Currently, I don't see it as a good entry point."

Richard Ross, global technical strategist at Auerbach Grayson, agrees with Gibbs. "I don't think this is a compelling entry point," he said. "I don't like it longer-term at these levels."

Ross points out that Apple's stock's good performance year-to-date (it's up 18.5 percent in 2014) is primarily due to the big jump in price since April. Though it was on an uptrend since then, the stock price has recently broken support and is now creeping towards its 50-day moving average, currently at $93.60.

"A break below the 50-day [moving average] is going to get some people's attention, certainly more technically-oriented traders," said Ross, a "Talking Numbers" contributor.

Yet it's the longer-term chart that really has Ross concerned. He sees Apple's stock price has having made a double bottom in the first half of 2013 after it reached all-time highs in 2012. It has since rebounded 68 percent in what Ross sees as a trend channel.

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We're into that obvious resistance, back at that old high, around that magical $100 level," Ross said. "We're also into resistance at the high end of that trend channel, that very well-defined trend channel. So this is a natural area for the stock to take a pause,"

There's also a fundamental worry for even a technical trader like Ross. "In the second quarter, four of every 10 smartphones globally were sold in China," he said. "I can name eight companies – if I could pronounce them – that have sold more smartphones in China than Apple. [It's] not a real big player over there for the time being, and that's a problem because that's where the growth is in this market. So just keep your eye on China insofar as it goes with iPhone sales."

To see the full discussion on Apple, with Gibbs on the fundamentals and Ross on the technicals, watch the above video.

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