A report projecting weak iPhone X orders temporarily trimmed some of Apple's stock growth on Tuesday.

J.P. Morgan analyst Narci Chang wrote in a research note that "high-end smartphones are clearly hitting a plateau this year." The note went on to predict that manufacturing of the iPhone X — the latest flagship phone — might be down 50 percent between the December and March quarters.

Shares remained up for the day in afternoon trading, hovering around $178 after a slight dip.

Chang's report comes as some skepticism has clouded Apple's usually-sunny outlook. In Taiwanese media and among some supply chain analysts, reports have indicated that Apple might be scaling back on its iPhone X production plans. Some Wall Street analysts have also weighed in, saying the handset's nearly $1,000 price tag might be accelerating a slump caused by the saturation of the smartphone market.

Others are more optimistic. Analysts at Canalys estimate that at 29 million units in the fourth quarter, the iPhone X was the world's best-shipping smartphone during the holidays — even if Wall Street doesn't feel that volume is up to snuff.

It's hard to know for sure whether demand is meeting expectations or if there's another cause behind the supply chain reports. Apple is notoriously secretive and has high expectations that manufacturers stay on the cutting edge, maintaining flexibility for design tweaks. The company did not immediately respond to a request for comment about J.P. Morgan's note.

— CNBC's Michael Bloom contributed to this report.