The Apple growth and profit machine is wavering, and the boost from price increases might not be enough to keep it going at historic rates. The pressure is on John Ternus to keep the momentum going.

Apple said its revenue grew 12% in the September quarter, slightly ahead of Wall Street's expectations. Its widely tracked gross profit margin, at 47.9%, also came in just ahead of analyst estimates. Apple's high-margin services business continues to slow, however.

Apple shares slumped 4% in after-hours trading as executives issued guidance that indicated the price increases that protected this quarter may be insufficient to buoy future quarters.

Chief Financial Officer Kevan Parekh said higher memory and storage costs hit Apple in the quarter as expected, but the company was able to offset the impact somewhat. "The price increases did provide some offset," he said in an interview.

When Ternus took over as Apple's third chief executive of the past 29 years on Sept. 1, he inherited sky-high expectations. The men he followed were among the most successful company leaders in American business history. Steve Jobs revolutionized consumer devices multiple times. Tim Cook expanded Jobs's creation to spectacular heights.

The expectations are reflected in Apple's huge valuation. Oppenheimer analyst Martin Yang noted that Apple stock trades at 36 times next year's expected earnings, a premium to the overall market, even though its earnings are only expected to grow 1%, which is slower than its tech peers.

"We see insufficient upside to justify the premium," Yang wrote in an investor note, adding that Apple needs to boost iPhone sales growth and turn around its slowing services business to make him more bullish.

Investors have bid up Apple shares because it has been a port in the AI storm -- a reliable and capital-efficient business that stands apart from rivals that are spending hundreds of billions of dollars racing to the AI frontier.

While others invest in data centers, Apple has been pouring its own cash into buybacks and dividends. But that safety may be challenged if Ternus can't speed up Apple's innovation engine.

Apple's lagging performance in AI was evident when its new "Siri AI" chatbot arrived this past quarter. Its long-maligned assistant was already stale the day it arrived, surpassed by agents such as Instinct and Muse that can complete multistep tasks for consumers, while Siri still sets kitchen timers.

Apple needs to give people reasons to buy its devices as they get more expensive. The company raised prices across the board last quarter to help offset the skyrocketing cost of memory and storage chips inside iPhones, iPads and Macs. Without compelling new features, a big question is whether consumers will slow the frequency of iPhone upgrades.

The new iPhone Duo appears to be a bright spot. Consumers are scooping up the $1,999 foldable smartphone despite mixed reviews -- so many that Apple can't keep up with demand. Shipping dates jumped out to January soon after the device went on sale, a disappointment for the normally reliable Apple supply chain.

The Duo is expected to be very popular in China, where foldable phones are already commonplace. So lack of Duo supply may explain why sales in China, which rose 21% from the prior year, fell short of the 28% growth analysts had predicted.

Apple will need to find new growth avenues because a reliable engine during the Tim Cook era -- the services business -- is slowing. Courts and regulators worldwide have limited Apple's ability to charge developers big fees to distribute apps through its App Store, the biggest component of the company's services segment.

One of its most lucrative App Store fee generators has been the ChatGPT app from OpenAI. Around the time Apple accused OpenAI of trade-secret theft this past summer, OpenAI began redirecting potential subscribers to pay via its website instead of the App Store, skirting Apple's tollbooth.

Apple's valuation has bumped up against a ceiling in recent weeks. Six times it traded above a $5 trillion market capitalization intraday before finally closing above the threshold, which it has already fallen back below.

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