Apple iPhone X volume expectations are still too high despite a recent correction in investor expectations, according to one Wall Street firm.

CLSA warned clients on Tuesday that with fourth-quarter phone sales expectations lower and first-quarter 2018 numbers unlikely to improve, the market may still be too bullish on Apple shares.

The company's stock closed down 2.5 percent last Tuesday, a day after Taiwan's Economic Daily reported the tech giant will cut its forecast for the iPhone X to 30 million from 50 million, citing unidentified sources. Shares are down more than 1 percent in the past month.

"We maintain that 2017 fourth-quarter iPhone X volumes were at 30 to 35 million and we are very skeptical that volumes will increase in the first quarter of 2018," CLSA analyst Nicolas Baratte wrote in an note Tuesday. "This does not reconcile with the expectation of pent-up demand or push-out to the first quarter of 2018 in our opinion: consumers who wanted to get an iPhone X in December 2017 already have it."

Apple declined to comment on the Taiwanese reports.

While Wall Street brokerages have come to different conclusions after the reports, Baratte argued that any expectations that forecast first-quarter volume over 35 million units "will prove too high." The analyst's comments come as the latest in a series of Street notes debating softer iPhone X expectations, with some firms still optimistic on mobile outlook.

Piper Jaffray reiterated its overweight rating and $200 price target on the company on Tuesday following a recent survey of iPhone users. Among its conclusions, the survey appeared to reinforce analyst Michael Olson's expectation that the mix of iPhones sold in fiscal year 2018 will include a significant number of new models.

"Our survey of 400 iPhone buyers indicates that iPhone X and iPhone 8 mix is similar to our expectations, increasing our confidence in average selling price assumptions for the current quarter and FY18," he wrote on Tuesday. "Our iPhone average selling price assumption of $720, therefore, appears achievable, increasing our confidence in revenue and earnings per share estimates."

Interestingly, both bullish Olson and skeptical Baratte noted that an iPhone X price cut could be an option for Apple in the new year if volume proves problematic.

"We expect a lower priced X-gen option (likely the current iPhone X with a price cut) and we wouldn't be surprised to see a 'plus' X-gen model in 2018," added Olson. Such a price reduction would likely test the "upper bounds" of what iPhone users are willing to pay, the analyst said, and could provide a cheaper option for those looking for more screen space on their smartphone.