The new iPhone 7 smartphone is displayed inside an Apple Inc. store in Los Angeles, California, U.S., Sept. 16, 2016. Wireless carriers are currently pushing promo plans for the new generation of iPhone. REUTERS/Lucy Nicholson

Following a rally in the price of shares for Apple Inc.’s (AAPL), a JPMorgan analyst told investors that while recent iPhone 7 promotions are helping boost demand, the rise might not be sustainable. In a client note Monday, Rod Hall said he thought the excitement over a climb in Apple’s shares was “premature."

Shares of Apple closed at $114.92 on Friday, after dropping to as low as $102.53 on Sept. 12. On Wednesday, the tech giant’s stock climbed more than four percent.

Hall released a statement to clients explaining the sudden spike, stating in part, “In the case of both AT&T and VZ, our Telco team believes volumes are up a little due to the more aggressive-than-expected promos but not substantial over prior expectations.”

“At present we believe the increased promos could pull the demand into the Sept. Qtr,” Hall added.

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Apple shares are up nine percent this year and are significantly higher following the debut of the highly anticipated iPhone 7. The new generation of iPhones, which officially hit stores Friday, gave way to a surge in demand and many of the models were completely sold out prior to the in-store debut of the new handsets.

The four top wireless carriers in the U.S. — Verizon, T-Mobile, Sprint and AT&T — are all pushing free upgrade promotion programs for the iPhone 7. Wireless carriers are promoting trade-in promo plans (for iPhone 6 and 6s trade-ins), which will most likely end in October, according to Hall.

Carriers T-Mobile and Sprint announced that their Apple iPhone 7 preorders were up nearly four times from the previous generation of iPhone 6 and 6s phones, CNN Money reported last Tuesday.

“It’s like four times bigger than the iPhone 6 for us at the preorder stage,” T-Mobile CEO John Legere stated in a broadcast last week.