NEW YORK - Apple is having its worst day of the year on growing fears that the iPhone X has not been a hit with customers.

Shares began to decline several days ago, and billions of the company's market capitalization has been erased.

J.P. Morgan analyst Narci Chang said last week that manufacturing of Apple's flagship phone, which go for at least $1,000 a pop, could be down 50 per cent between the December and March quarters.

Shares of Apple Inc. fell 2.5 per cent Monday, the worst trading day so far in 2018. Shares did hit an all-time high earlier this month.

Apple did not immediately respond to a request for comment. The company is scheduled to report first-quarter earnings Thursday.