Apple stock caught a downgrade from KeyBanc on Tuesday, as analyst Brandon Nispel warned that investors may prove less willing to pay a hefty premium for the iPhone maker's shares as growth falters.

Nispel cut his rating for Apple to Underweight from Sector Weight, assigning the stock a $250 price target that implies it will drop about 21% from its level as of Monday's close.

Shares took a hit, sliding 1.1% to $313.84 ahead of Tuesday's opening bell. Futures tracking the S&P 500 were 0.1% lower.

Nispel wrote in a research note that KeyBanc spending checks had signaled "another month of below-trend growth" for Apple in June, adding that growth was starting to fade after a boost in 2025.

The analyst flagged sluggish iPhone sales, weakness in other products like Macs and iPads, and the knock-on effect that the slowdown would have on revenue for services like iCloud and Apple Music.

Nispel added that those three factors would soon make the stock look "too expensive." Apple fetches 36-times expected earnings for fiscal 2026, a premium to both its five-year average and the S&P 500.

The shares have risen 17% so far this year, although investors have been worrying about price hikes in recent weeks.

Apple said in late June that it would jack up the cost of MacBooks and iPads, as it scrambles to keep up with a recent surge in memory costs.