While Apple fans are hungry for a new iPhone, some analysts are warning investors from "aggressively buying" the company's stock ahead of its event on Tuesday.
"Everyone is interested and excited in what the company will do on Tuesday, but I don't know if that warrants getting aggressive ahead of what we don't know," said Scott Kessler, an analyst at S&P Capital IQ.
"Apple has done a great job at surprising and delighting consumers and putting down skeptics, but that doesn't mean they are going to be able to keep doing that," he said.
With the exception of the iPhone 5 release, Apple's six-month and 12-month returns after the release of a new iPhone have been generally positive for shareholders, even though the stock usually drops immediately after a product launch.
(See how Apple's stock performed after each major product launch since 2007 in our series of charts below)
But this release could be different, Kessler said.
The analyst, who has a "hold" rating on the stock with a price target of $103, said there's more questions surrounding this Apple event than previous ones.
"The question is what's next for the company, and is a wearable device going to be the next big product? I don't know and I don't have a tremendous amount of confidence that a wearable is it. And even if it did become popular, could it really move the needle for a company Apple's size?" Kessler said.
The iPad was previously a growth driver for Apple, but it's now had two straight quarters of significant declines, Kessler said. And while the iPhone continues to be Apple's strongest growth business, the momentum can't last forever, analysts said.
"The bread and butter of Apple's revenue is the iPhone. So the iPhone 6 is critical for the company," said J.P. Gownder, a vice president and analyst at Forrester. "But if they want to continue to be seen as a growth company, then they need to create a new category."
So far, Apple has continued to put its devices in more peoples' hands. Its deal with China Mobile has enabled Apple to grow its international market share, and its recent partnership with IBM gives it some stronger footing in the enterprise.
But competition in the smartphone and tablet space continues to intensify and if Apple plans to launch a bigger iPhone, it could potentially cannibalize some of its iPad sales, Kessler said.
The company's stock had its worst day since January on Wednesday, . The decline followed Samsung's announcement of two new smartphones as well as news that some celebrities' iCloud accounts had been breached in highly targeted attacks.
(See how Apple's stock performed six and 12 months after a product launch below)
In a note on Wednesday, Pacific Crest Securities analyst Andy Hargreaves also warned investors to take profits now because neither a new iPhone 6 or a smartwatch could drive meaningful growth for the company in the long term.
Read More Take profits in Apple now: Analyst
"The big issue we see has nothing to do with the next couple quarters, quite frankly we think they are going to be fantastic. But once you get through the iPhone 6 cycle, you have the really difficult comps and you're back to dealing with saturated markets, that means growth slows, multiple contracts and it's hard to get the stock higher," Hargreaves, who has an "outperform" rating on the stock with a price target of $100, said on CNBC's "" on Thursday.
And as for a smartwatch, Hargreaves said that he's skeptical a wearable device would have a significant impact for long-term growth.
"I'm not saying there is no way. There is a very, very small percentage chance that they find the way," he said. "I think they are going to have to find something that changes the world, to be quite frank. It's going to have to be not only massively valuable to consumers on an everyday basis, but it has to be something that a lot of people can buy."
(Not all stock analysts agree, of course. CNBC's Jim Cramer explains here why he's still very bullish on the company.)
—By CNBC's Cadie Thompson