Apple Shares Wobble as Antitrust Suit Takes Aim at Growth Pillar

For years, Apple Inc. investors have consoled themselves with the idea that no matter what trends look like for major product categories, growth in services would remain robust. Now, the outlook for that business is on shakier footing.

Its shares fell the most since August on Thursday, after the Justice Department filed a suit accusing Apple of violating antitrust laws and suppressing competition by blocking rivals from accessing hardware and software features on its popular devices.

The decline also brings Apple’s year-to-date slide near 11%, erasing $337 billion from its market capitalization. The selloff stands in contrast to the rest ...