Apple's stock traded higher after hours on better-than-expected quarterly earnings results, but long-term risks for the company remain, BGC Financials Director of Research Colin Gillis said Monday.
Earnings per share came in at $1.42 on revenue of $42.1 billion, easily beating Wall Street forecasts. The company also gave sales guidance for the current quarter of $63.5 billion to $66.5 billion, at the high end of analysts' estimates.
"(Apple) Pay is a nice service product. You're going to make 14 cents on every $100 purchased. So, that's going to take a long time to ramp up, but we like the annuity component to it. (Apple) Watch is a gigantic question mark," Gillis said.
On CNBC's "Fast Money," Gillis also pointed out a 14 percent decline in revenue from iPad sales.
"Could this happen to the iPhone? Could units become good enough that the upgrade cycle lengthens out? And that's the long-term risk for Apple," he added.
Gillis has a "hold" rating on the stock and a price target of $98 per share.
Apple, he added, could become a victim of its own success.
"There's absolutely a chance that the iPhone could fall out of favor at some point, or that sales could slow down. That's the core of this issue," he said. "It's not going to happen on this cycle, but it could happen on the next cycle because, again, thinner and faster, at some point, is going to become less of a reason to drive to the next phone."
Apple stock, which closed up 2 percent at $99.76 per share, traded above $101 in after-hours trading, a muted reaction that wasn't lost on Gillis.
"Apple has to smash records to push this stock forward, and that's a tough spot to be in," he said. "Watch could be another home run, but expectations for it are already quite hot, and so it's going to be hard to have upside to those expectations."
RiskReversal.com's Dan Nathan also saw potential headwinds in Apple's robust outlook for the current quarter, as well as lagging iPad sales and the unproven Apple Pay.
"There is a potential that this thing does not turn out to be a runaway hit, and so those are the catalysts that you have to look out for in the new year," he added.
Triogem Asset Management's Tim Seymour said Apple stock still had plenty of steam left, noting the robust user base of iTunes.
"They haven't even begun to monetize this part of their world," he added.
Guy Adami of Private Advisor Group reiterated that he had thought Apple stock would head down toward $88 the last time it was at $101. But he didn't sound bearish this time around.
"There's really nothing to knock at. Margins are good," he said. "This should be the quarter to take it to that $110 level."
Karen Finerman of Metropolitan Capital Advisors, who owns Apple stock and shorted calls against it, also noted the subdued after-hours action.
"That gives me some pause," she said. "Maybe the run is over. I would've thought it would do better on this news."