The market’s anticipation of strong sales from the new iPhones drove Apple shares much higher this year, but now one Wall Street firm says optimism for big upside is not warranted.

Wells Fargo Securities reiterated its market perform rating for Apple shares, saying the latest China export data points to meager iPhone sales growth in the December quarter.

“An analysis of China Province-level mobile phone export data this week reinforces our cautious opinion on Apple’s iPhone cycle,” analyst Aaron Rakers wrote in a note to clients Wednesday entitled “iPhone-Related China Data Analysis: Implying Limited / No Yr/Yr Growth Thus Far In 4Q17.”

The analyst wrote they “currently see limited/no upside potential to our 81.2M iPhone ship estimate.”

Apple is one of the market’s best-performing large-cap stocks of 2017, rallying 47 percent year to date through Wednesday versus the S&P 500’s 20 percent gain.

Rakers noted the combined October and November phone exports in key iPhone related Chinese provinces of Henan, Shanghai, Shanxi, and Jiangsu were up only 0.6 percent year-over-year. He also said November phone exports out of Zhengzhou Customs, the largest port for iPhone shipments, were up 17 percent year-over-year in dollars, but down 8 percent year-over-year in units.

The analyst reaffirmed his $195 price target for Apple shares, which is 14 percent higher than Wednesday’s closing price.

Apple did not immediately respond to a request for comment.