Why Apple stock will 'grind higher': Analyst

A flood of Apple Watch pre-orders is pushing back shipping times of the much-hyped wearable by weeks—in some cases, months. That bodes well for Apple investors, according to RBC Capital Markets' Amit Daryanani.

"It's either a sign that demand is really good or supply is really constrained, but it looks like they have a healthy backlog already," the analyst told CNBC on Friday.

Read MoreHereare the latest Apple Watch wait times

Daryanani holds an "outperform" rating on Apple stock and believes the shares should "grind higher" to his price target between $140 and $145. He expects Apple to ship about 3 million to 5 million watch units in its first few months, about 1 million coming from pre-orders.

"Most of the reviews suggest that it's one of the best first-gen [smart] watches you've seen out there, and the potential is immense as you go further out," he said. "From a review basis, this is pretty good for Apple investors."