The thieves grabbed the shipment off a UPS truck before they were delivered to an Apple Store at the Stonestown Mall.
Police said a witness saw three suspects wearing hooded sweatshirts come out of a white Dodge van.
Authorities believe the suspects were tracking the truck and made their move when the driver went into Macy's to make a delivery.
Police said at least 300 iPhone X's were stolen, making off with more than $300,000 in merchandise.