FedEx added 1.1% to $123.59 a share after Bank of America analyst Ken Hoexter lifted his rating to buy from neutral.
The Bank of America analyst also boosted his price target on the Memphis overnight-delivery giant to $140 a share from $117, an increase of more than 19%.
The analyst's new target also represents a premium of more than 14% over its current trading price.
In his note to investors, Hoexter contends Amazon's decisipn reflects the challenges the tech giant faces in trying to build a new player in the highly competitive delivery field.
He also sees potential network cost savings in FedEx's move to combine its ground and express services for some e-commerce orders.
Amid a flood of online orders, FedEx in March began to use its ground service to transport some residential express packages the last few miles.
The move, in turn, frees up its express unit to focus on more lucrative business-to-business deliveries, FedEx has said.
News of Amazon's decision last week to suspend its delivery service sparked a rally in FedEx shares. FedEx last year terminated a deal to ship Amazon packages in the wake of the competitive threat.
J.P. Morgan, in a note to clients after the Amazon decision, also saw FedEx as one of the biggest beneficiaries of the Seattle retail-and-tech giant's move to suspend Amazon Shipping.